In a large pot add butter and olive oil. Over medium high heat sauté onion, celery and garlic until tender. Add the flour to create a roux and cook for another minute.: The kitchen will begin to smell warm and inviting as the butter melts and the olive oil smooths the heat, creating a glossy surface for the vegetables. You want the fat to shimmer but not smoke, because burnt fat will give a bitter edge. A common mistake here is overheating too fast, which browns the butter prematurely; watch for small bubbles and a gentle sizzle to know the temperature is right.
Slowly add the half and half and chicken broth and stir until it starts to thicken. Add the thyme, carrots, spinach, chicken and gnocchi. Simmer for about 5 minutes or until gnocchi is cooked and soup is thickened. (If you want a thinner soup add another can of chicken broth.) Salt and pepper to taste and serve immediately.: As you add the diced onion and celery , you will hear a soft sizzle and soon see the onion turn translucent and glossy while the celery relaxes. Add the minced garlic after the onion softens so it becomes fragrant without burning; burnt garlic tastes acrid. Stir frequently for even color, and avoid browning too much because the aim is sweetness and aromatic lift.
Add the flour to create a roux and cook for another minute: When you sprinkle in the all-purpose flour , it will bind with the fats to form a paste that looks slightly... grainy at first, then smooths out as you stir. Cooking for about a minute removes raw flour taste; you will notice a faint nutty scent when it is ready. Do not let it darken, because that will reduce its thickening power and add an unwanted toasted flavor.
Slowly add the half and half and chicken broth and stir until it starts to thicken: Pour the half-and-half gradually while whisking so the mixture becomes glossy and lump free, then introduce the chicken broth . You will see the liquid gain body, transforming into a velvety sauce that clings to the spoon. If you add the cold liquid too quickly, you can get lumps or a sudden shock that cools the pot; temper the liquid slowly for the smoothest texture.
Add the thyme, carrots, spinach, chicken and gnocchi: As you fold in the thyme , shredded carrots , chopped spinach , diced chicken , and package of potato gnocchi , the pot will come alive with color and aroma. The vegetables will begin to soften, and the gnocchi will bob gently as they cook. Stir to combine so nothing sticks to the bottom, and be careful not to overfill the pot, which can prevent even cooking.
Simmer for about 5 minutes or until gnocchi is cooked and soup is thickened: A soft bubbling should ripple across the surface as the soup simmers, and you will notice the gnocchi become tender and plump. The broth will coat the ingredients and cling to the spoon when it is ready. Over simmering can make the gnocchi fall apart, so test one for a tender, slightly chewy center and then remove from heat to preserve texture.
If you want a thinner soup add another can of chicken broth: Adding another 14 ounce can of chicken broth will loosen the consistency and make the bowl more brothy. The sound of the liquid will smooth out into gentle simmering, and the soup will taste a touch lighter. A common oversight is adding the extra broth without adjusting seasoning; taste after thinning and add salt and pepper accordingly.
Salt and pepper to taste and serve immediately: Finish with careful seasoning using salt and pepper , tasting as you go until the soup sings. The final bowl should feel balanced, with the creaminess lifted by the seasoning. Serve right away so the gnocchi maintains its tender texture, and avoid letting it sit too long which can soften the dumplings further.