Step 1

Arrange a rack in the middle of the oven and heat the oven to 350°F.

Step 2

Dice 1 medium yellow onion (about 1 1/2 cups) and 1 medium green bell pepper (about 1 cup). Finely chop 3 garlic cloves. Cut 8 ounces sliced bacon crosswise into 1/4-inch pieces. Drain and rinse 1 (about 15-ounce) can each of pinto, kidney, and cannellini beans.

Step 3

Place the bacon in a Dutch oven and cook over medium heat, stirring occasionally, until browned and crisp, 7 to 10 minutes. Use a slotted spoon to transfer the bacon to a paper towel-lined plate. Remove all but 1 tablespoon of bacon fat from the pot; discard the remaining fat.

Step 4

Add the onion and bell pepper to the pot and cook over medium heat, stirring occasionally, until softened, 5 to 7 minutes. Add the garlic, 1 tablespoon chili powder, and 1/8 teaspoon cayenne if using, and stir to combine. Cook, stirring frequently, until fragrant, about 1 minute.

Step 5

Add 1 pound lean ground beef, 1 teaspoon kosher salt, and 1/4 teaspoon black pepper. Cook, breaking up the meat with a wooden spoon into small pieces and scraping up the browned bits at the bottom of the pot, until the beef is cooked through and browned, 4 to 5 minutes.

Step 6

Add the beans, bacon, 1 cup water, 1/4 cup tomato-based barbecue sauce, 1/4 cup packed brown sugar, 1/4 cup ketchup, and 1 tablespoon Dijon mustard. Stir to combine and bring to a simmer.

Step 7

Cover and transfer the pot to the oven. Bake until the flavors meld and the sauce is thickened, about 45 minutes. Taste and season with more kosher salt as needed. Serve with desired toppings.