Melt the butter in the olive oil over medium-high heat in a large Dutch oven or soup pot. Add the chopped chicken, onions, jalapenos, and seasonings; then sauté for 3 minutes.: As the fats warm, you should notice a glossy shimmer and a gentle sizzle when a piece of chicken hits the surface. This combination helps prevent scorching while letting the chicken develop a golden edge that adds savory depth to the final chowder. You want audible, steady sizzling, not furious sputtering; if it spits aggressively, the pan is too hot and you should reduce heat immediately. A common mistake here is overcrowding the pot, which causes the chicken to steam instead of brown, resulting in less flavor. The aroma will turn richer as the onion softens and the spices bloom in the fat, signaling readiness for the next ingredients.
Add the bell peppers, garlic, and flour. Cook, while stirring for 2 minutes.: During these first few minutes the onion should go from opaque to translucent and the jalapeño will soften while releasing its green pepper notes into the oil. The spices will become fragrant, almost perfume like, which indicates they are blooming properly. If the spices smell sharp or burned, the heat is too high and you should lower it. Stir frequently to ensure even cooking and to stop any bits from sticking to the bottom, which can impart burnt flavors to the chowder.
Reduce the heat to low and gradually stir in 3 cups chicken broth.: As you stir, the flour will lose its raw edge and begin to take on a nutty aroma, which is important for a smooth, cooked-through thickening base. The bell pepper should soften but keep some body, offering a sweet counterpoint to the chilies. If the mixture becomes dry or starts to stick, add a splash of the reserved broth to loosen it, avoiding lumps. A typical pitfall is rushing and not cooking the flour long enough, which can leave a chalky texture in the finished chowder.
Whisk 2 tablespoons cornstarch with the remaining 1 cup chicken broth and add it to the soup. Stir in the creamed corn, whole corn, diced tomatoes, and green chiles.: Adding the broth slowly while stirring helps incorporate the flour paste into the liquid, preventing lumps and creating a satin texture. You will notice the mixture ease into a more liquid state and begin to smell fuller and more rounded. Keep the heat gentle so the starches hydrate evenly, and stir until smooth. If small clumps appear, whisk vigorously or strain the liquid, but prevention by gradual addition is best practice.
Bring to a boil, then reduce to a simmer. Add rotisserie chicken if using. Simmer, uncovered, for 10 minutes, stirring occasionally.: This slurry technique gives a glossy, stable body to the chowder without making it stodgy. When you add the slurry and canned items, the pot will look thicker and the aroma will brighten from the tomatoes. Stir thoroughly so the cornstarch activates uniformly; if you add it straight to hot liquid without dissolving, it can clump. One common error is adding the slurry at too high a temperature which can cause rapid thickening in uneven pockets, so temper and stir continuously as you combine.
Reduce the heat to low, and stir in the softened cream cheese until melted. Then, add the shredded cheeses, a handful at a time, and continue to stir until completely melted.: When the pot reaches a boil you will see steady bubbles and a rising steam column; reduce to a gentle simmer so flavors meld and the corn softens without breaking apart. If using pre cooked rotisserie chicken , add it now to warm through and meld flavors. Stir occasionally to avoid sticking and to check thickness, because simmering concentrates the liquid and intensifies seasoning. A mistake here is leaving the pot at a high boil which can cause dairy or cheeses added later to separate, and it can make the corn kernels lose structure.
Garnish servings with desired toppings.: As the cream cheese melts, the chowder will become visibly silkier and the surface will take on a glossy sheen. Adding shredded cheeses gradually prevents them from clumping into oily ribbons and encourages smooth emulsification. Pay attention to texture and keep the heat low, as overheating can cause the cheeses to seize and release fat, resulting in a greasy mouthfeel. If this happens, remove from heat and whisk in a splash of warm broth to bring it back together.
Garnish servings with desired toppings: The final garnishes transform the bowl into a composed dish, adding brightness, creaminess, and crunch. A spoonful of sour cream cools and fattens the edge, while chopped cilantro adds fresh herb notes and crushed tortilla chips introduce textural contrast. Taste for final seasoning here and add hot sauce sparingly to balance. A common oversight is over topping, which can overwhelm the chowder base; add toppings thoughtfully to complement, not mask, the flavors.