Preheat oven to 300 degrees F. To a baking sheet, add the halved roma tomatoes and halved hatch chiles. Sprinkle the tomatoes and chiles with salt and drizzle the tomatoes with one tablespoon of olive oil. Transfer to the oven to roast for about 1 hour, until they’re super juicy and a little shriveled up. Let them cool slightly on your kitchen counter.: Warmth will coax out juices without burning the skins, and you should notice the aroma changing from grassy to sweet as they slowly roast. The tomatoes will soften and the surface will wrinkle, giving a glossy, concentrated look. If the oven is too hot the skins brown too quickly, losing that jammy interior, so keep it steady at the specified heat.
To a small sauté pan, set over medium heat, add a tablespoon of olive oil. When warm, add the chopped onion and garlic cloves. Cook until softened about 5 minutes. Transfer to a blender.: When arranged cut side up, the tomatoes will steam and caramelize in place, releasing sticky, fragrant juices, while the chiles develop gentle char spots. You should see beads of juice collecting and smell a roasted tomato perfume. Crowding the pan prevents even roasting, so leave space or use two sheets if necessary.
Using a pair of tongs, add the roasted tomato and one of the hatch chiles (we’re gonna use the other hatch chile for the grilled cheese). You may need to do this in batches depending on the size of your blender. Pulse until smooth, about 1 minute. Pour the soup into medium pot, set over medium-low heat. Add about 1/4 cup of water to the blender (you can eyeball this) and swish it around to get all the leftover soup off the sides of the blender. And pour that water/soup mixture to the pot.: The tiny crystals of salt pull moisture from the flesh, concentrating flavor, while the olive oil encourages caramelization and gives a silky sheen to the finished soup. The sprinkle should be even but light, so you do not overdry the fruit. Oversalting at this stage can make the soup too salty after reduction, so taste later before final seasoning.
Bring to a gentle simmer for about 20 minutes, just so all of the flavors merry together. Give it a taste and add salt to taste. I added about 2 teaspoons.: Look for concentrated, slightly wrinkled skins and a deepened color, with the tomatoes losing their raw brightness. The oven will fill with a warm, savory-sweet scent. If you pull them too early the soup will taste watery, and if left too long they risk bitterness from charred flesh.
Meanwhile, make the grilled cheese. I think grilled cheeses are a bit personal. But I like to smear softened butter on the outside slices of the grilled cheese. I add about 1/2 cup of shredded cheese to each grilled cheese and a handful of the diced hatch chiles. I add the grilled cheese to a non-stick skillet over medium-low heat. And then cover it with a lid. I cook the grilled cheese for about 3 minutes per side. And that’s it!: Cooling makes handling safer and helps the skins separate from flesh in the blender. You will notice steam dissipating and the aroma settling into a richer profile. Blending very hot can create pressure in some blenders, so patience here prevents messy splatters and potential burns.
Serve with soup.: The oil should shimmer gently when warm, not smoke. This stage builds the aromatic base, and the sound will be a soft sizzle when you add aromatics. If the pan is too hot the aromatics will brown too fast and become bitter, so use medium heat for control.
When warm, add the chopped onion and garlic cloves: You will hear a gentle sizzle and smell the onion sweeten as it softens and translucence appears. Cook until tender, about 5 minutes, stirring to avoid browning. Browning too quickly will introduce a bitter note, so keep the heat moderate and move the pan lovingly while it cooks.
Cook until softened about 5 minutes: The onion should lose its raw edge and the garlic should smell nutty and fragrant. This softened base deepens the soup and creates savory layers, so don’t rush this step with high heat. A common mistake is to undercook the aromatics which leaves a raw bite; take the extra minute if needed.
Transfer to a blender: Add the softened aromatics to the blender in batches if needed; you want an even puree. You should notice the mixture becoming glossy and aromatic, with no large pieces remaining. Overfilling the blender risks uneven blending and splatters, so pulse in controlled amounts for safety and consistency.
Using a pair of tongs, add the roasted tomato and one of the hatch chiles: The roasted pieces will be softened and glossy, and using tongs keeps your hands safe from heat. Add them gradually so the blender can manage the load. If your blender is small, do this in batches to avoid splashing, and remember to reserve the second chile for the sandwich.
You may need to do this in batches depending on the size of your blender: Blending in batches ensures a smooth, lump free texture and avoids overheating the motor. After each batch pulse until silky, scraping down the sides with a spatula if necessary to get everything incorporated. Overfilling or running the blender too long in one go can lead to a warmed, diluted consistency and uneven texture.
Pulse until smooth, about 1 minute: You should see a glossy, uniform puree with steam rising and a bright, roasted aroma. The sound will change from harsh to a steady hum as the texture becomes even. Pulsing too briefly leaves chunks, while running it excessively can heat the soup too much and alter the fresh flavor.
Pour the soup into medium pot, set over medium-low heat: The moment the puree hits the pot you’ll notice its perfume deepen as it warms. Medium low lets flavors meld without aggressive boiling, preserving brightness. Boiling hard can dull the nuanced roasted notes and cause the soup to lose some silkiness.
Add about 1/4 cup of water to the blender and swish it around to get all the leftover soup off the sides: This small rinse picks up concentrated bits and ensures nothing flavorful is wasted. You will see a thin, tomato tinted liquid that helps thin the pot mixture without losing intensity. Skipping this step can leave delicious fragments clinging to the blender, diminishing the final yield.
Pour that water/soup mixture to the pot: The combined liquid will unify textures and flavors, and you should notice a uniform color and consistency as things come together. Stir gently to combine. If you skip this, the pot may end up a touch thicker and less cohesive, so the rinse matters.
Bring to a gentle simmer for about 20 minutes, just so all of the flavors marry together: On the stovetop you’ll see small, slow bubbles and smell the layers blending into a rounded, mellow bowl. Simmering allows acids to mellow and aromatics to integrate. Avoid a rolling boil which can break down textural elements and evaporate too much liquid, concentrating flavors unevenly.
Give it a taste and add salt to taste: Tasting here is critical since roasting concentrated the flavors, and you may need more or less salt than expected. I often end up adding about 2 teaspoons total, but adjust to your preference. A common misstep is adding too much at once; season gradually and taste between additions.
Meanwhile, make the grilled cheese: The smell of butter hitting the pan should be warm and inviting, and the bread will sizzle as it crisps. Melting cheese and diced roasted chile inside creates texture and pockets of heat that contrast the soup’s silk. Use medium low heat so the bread browns slowly while the interior melts evenly.
I smear softened butter on the outside slices of the grilled cheese: Butter on the exterior yields a golden, evenly crisp crust with a rich aroma. You should hear a steady sizzle and see beautiful browning within a few minutes. Using too much heat can brown the outside before the cheese melts, so moderate heat is your friend.
I add about 1/2 cup of shredded cheese to each grilled cheese and a handful of the diced hatch chiles: The cheese should melt into a gooey center while the diced chiles provide bursts of flavor. Watch for a stretchy, molten interior when you press gently. Overstuffing can lead to leaks and messy pans, so keep fillings balanced.
I add the grilled cheese to a non-stick skillet over medium-low heat and then cover it with a lid: Covering traps warmth, encouraging the cheese to melt fully while the exterior crisps. You will notice steam rise and the sandwich compress slightly as the cheese becomes molten. If you skip the lid, the outside may brown before the inside reaches the perfect melt.
I cook the grilled cheese for about 3 minutes per side: Look for an even golden brown and a soft, melty center. The sizzle will quiet and the sandwich will feel slightly pliant when the cheese is ready. Flip gently with a spatula to keep the filling intact. Rushing flips or using high heat causes uneven browning and incomplete melting.
Serve with soup: Present the bowl warm with the grilled cheese alongside or broken into pieces for dunking. You should experience the mix of smoky, sweet soup and buttery, cheesy bread in each spoonful. If the soup has cooled, briefly rewarm on low to preserve texture and flavor before serving.