Place a large pot over medium-high heat and add 2 turns of the pan of EVOO, about 2 tablespoons. Add the chicken bits and brown them, about 5-6 minutes. Add the carrot, onion, celery, garlic, paprika, bay leaf and some salt and freshly ground black pepper. Cook the veggies, stirring frequently, until tender, 3-4 minutes. Add the chicken stock and scrape up any brown bits from the bottom of the pot. Add the hot sauce and crushed tomatoes, and bring up to a bubble. Simmer the chili for 8-10 minutes to let the flavors come together and thicken it slightly.
While the chili is simmering, toss the pasta into the boiling salted water and cook until al dente according to package directions. Once cooked, drain the pasta and toss it into the chili, then transfer everything to a casserole dish. Sprinkle the cheeses evenly over the top and place it under the broiler until the cheeses have melted and the top is golden brown, 2-3 minutes.
Sprinkle the chopped scallions over the top and watch this one disappear in no time.