Heat oil in a 5- to 6-quart Dutch oven over medium heat. Add bacon and cook, stirring occasionally, until fat renders and bacon crisps, about 4 minutes. Transfer bacon with a slotted spoon to a paper towel–lined plate, leaving fat in pot.
6 ounces thick-cut bacon
Increase heat to medium-high; add sausage in a single layer and cook until browned, about 2 minutes. Stir and cook until lightly browned on the other side, about 2 more minutes. Transfer to plate with bacon.
1 pound smoked sausage
Add onion to pot and cook, stirring occasionally, until soft, 3 to 4 minutes. Add garlic and thyme and cook until fragrant, about 30 seconds. Stir in tomato paste and cook until it darkens, about 1 minute.
1 medium yellow onion, 4 cloves garlic, 2 teaspoons fresh thyme leaves, 1 tablespoon tomato paste
Pour in chicken broth, scraping up browned bits with a wooden spoon. Bring to a simmer, then add beans (undrained), bacon, sausage, chicken thighs, and bay leaf. Season with salt and pepper to taste.
4 cups low-sodium chicken broth, 4 cans cannellini beans, 6 ounces thick-cut bacon, 1 pound smoked sausage, 1.5 pounds boneless skinless chicken thighs, 1 bay leaf
Cover pot and transfer to a 350°F oven. Bake until chicken is cooked through and sauce thickens, about 45 minutes.
1.5 pounds boneless skinless chicken thighs