Char the bell peppers, jalapeƱos, and poblanos under the broiler or over a gas flame until blackened. Place in a covered bowl for 10 minutes, then peel, seed, and dice.
Heat olive oil in a large Dutch oven over medium-high heat. Add ground beef and Italian sausage, breaking up with a spoon, and cook until browned, about 8-10 minutes. Drain excess fat.
Add onion and garlic to the pot and cook until softened, about 5 minutes. Stir in chili powder, cumin, smoked paprika, and cayenne, cooking for 1 minute until fragrant.
Add the charred peppers, diced tomatoes, tomato paste, kidney beans, and beef broth. Stir well to combine.
Bring to a boil, then reduce heat to low and simmer uncovered for 2 hours, stirring occasionally, until thickened and flavors have melded.
Season with salt and black pepper to taste. Serve hot with your favorite toppings like shredded cheese, sour cream, and green onions.