Press the sauté button on an electric pressure cooker. Add the turkey and brown the meat, using a wooden spoon to break it into small pieces as it cooks, 4 to 5 minutes. Drain the meat and transfer it to a small bowl.: You will smell a toasty, meaty aroma as the turkey browns, and small sizzling pops will let you know moisture is evaporating and flavor is concentrating. The visual cue is specks of golden brown on the meat, not gray and steamed. Browning creates the Maillard reaction which adds depth, so do not rush this stage or you will lose richness. A common mistake is overcrowding the pot, which causes steaming instead of browning; if that happens, brown in batches to get color. After draining, the meat should be dry to the touch and richly scented, which is perfect for returning later.
In the pressure cooker (still on sauté), melt the butter. Add the onion, carrots, celery, and garlic. Cook, stirring, until softened, about 5 minutes. Add the flour, salt, and pepper to taste and cook, stirring, for 1 minute to cook the flour. Return the turkey to the pressure cooker and add the chicken broth, potatoes, and cauliflower and stir.: As the butter melts, it releases a nutty scent that helps carry the aromatics. You want the onion translucent and the carrots and celery softened so they release sweetness, a process you will hear as steady gentle sizzling rather than frantic popping. When you sprinkle in the flour , it should foam slightly as it cooks, indicating the raw edge is gone; this step thickens the final soup and prevents a raw pasty taste. Stir constantly to avoid lumps and to coat the vegetables. Returning the browned turkey at this point layers flavors, and adding the chicken broth , potatoes , and cauliflower builds the cooking liquid. A frequent error here is undercooking the flour, which leaves a pasty texture, so give it that full minute of gentle stirring.
Seal and cook on high pressure for 10 minutes, until the potatoes are soft. Quick release, then open when the pressure subsides.: Once sealed, you will notice the cooker settling into a low hum as pressure builds, and the smell will deepen into a concentrated savory steam. The timing lets the diced potatoes become tender without falling apart. After the quick release, the lid will drop and a burst of aromatic steam will escape, confirming doneness. Avoid the mistake of leaving the potatoes undercooked; if a fork does not easily slide through, reseal and give it a few more minutes. Conversely, overcooking can make the vegetables mushy, so follow the timing closely for the intended texture.
Transfer the cauliflower and 1 cup of the liquid to a blender and blend until smooth. Pour the puree into the soup and stir well. Add the cheddar and stir until melted. Serve topped with the scallions.: The pureed cauliflower transforms the broth into a silky base, and you will notice a creamier mouthfeel and a slightly sweet vegetal aroma. When you blend, the liquid should be warm but not scalding to avoid steam pressure in the blender; hold the lid with a towel and pulse gently. Pouring the puree back in will thicken and brighten the soup visually as it becomes glossy. Adding the shredded cheese off the heat prevents separation and creates that melty, cohesive finish. A common pitfall is overheating the cheese , which causes oil to separate, so stir gently until just melted. Garnish with chopped scallions for a fresh contrast in texture and flavor.
To make this in a large pot or Dutch oven, sauté over medium-high heat in steps 1 and 2. For step 3, bring to a boil, then cook, covered, over low heat until the potatoes and cauliflower are tender, 25 to 30 minutes. Transfer 1 cup of the liquid and the whole cauliflower to the blender, and blend until smooth. Stir the puree into the soup, add the cheddar, and serve topped with the scallions.: On the stovetop you will hear a gentle simmer spreading across the pot as the flavors meld, with periodic light bubbling and a deepening aroma. The longer, gentler cook allows starches to release slowly for a hearty texture; watch for steady simmering rather than a rolling boil that can break down ingredients unevenly. When you remove the cup of liquid and cauliflower for blending, it should look milky and fragrant, an indicator the vegetables are properly softened. A typical mistake is boiling too aggressively which can make the soup cloudy and separate the cheese later, so keep it to a gentle simmer and check doneness with a fork.