Rather than the small sweet peppers, you can use bell peppers of your choosing. I prefer them because with their thin skin they cook at about the same rate as poblanos; it's generally 1.5 cups of peppers. It's also probably faster to chop only 3 peppers instead of 16, but then I'd have to change the name of the recipe. I also chop the hotter peppers much larger than I used to so I can serve the chili to my son after I scoop them out; if you'd prefer to dice them, it works great - that's what I used to do. You can skip ancho and just use regular chili powder to your taste. I serve my chili with chopped green or red onion and shredded cheese; sometimes a little chopped cilantro. For my son we give him a few dollops of plain yogurt as well. —Sklyon
Chop onion in a fine dice. Remove stems, veins and seeds from serranos and jalapeños and slice thinly crosswise.
Roughly chop the garlic.
Remove the veins and seeds from the poblanos and sweet peppers and cut into roughly half inch squares. (These first three steps can be done beforehand and kept in separate airtight containers in the fridge overnight.)
Heat a good glug of your oil of choice in a soup pot over medium heat. When hot, add the onions and hot peppers with a pinch of kosher salt. Stir every minute or so, making sure to soften but not brown. 6-8 minutes.
Add the garlic and turkey to the pot. Before adding store-bought ground turkey, I like to run a paring knife through the meat in a crisscross pattern to help it break down in the pot. Turn the heat up a little and smush the meat to break it up and help it brown.
Add the tomato paste and the spices. Stir a lot. Brown that meat. Manage the heat on your burners. If you see the onion or anything else beginning to crisp, turn the heat down.
Add the poblanos and peppers once the meat is nearly browned. Stir every now and then. You want to soften the peppers without melting them and also make sure the meat is cooked through.
Add all the tomatoes and beans with another pinch of salt and cook until the peppers are tender on the lowest simmer possible on your stove. Taste the broth for your preferred "chiliness" and adjust if needed. If it's too spicy, you can always throw in some chopped soft corn tortillas to numb it or serve with yogurt or sour cream.
Add corn. Simmer 5 more minutes or until the corn is heated through, but maintains its bite.