Slow cook the chicken thighs with the Worcestershire, garlic, dijon, salt, garlic powder, onion powder, black pepper, thyme, beef bone broth, and rosemary sprig for 3-4 hours on high or 4-5 hours on low.
Make the caramelized onions/French onion base by sautéing the diced yellow onions in butter until caramelized. Add the beef bone broth, Worcestershire, soy sauce, and Dijon. Optionally add a sprig of rosemary and thyme.
Make the cheese sauce by blending the cottage cheese, Gruyère, Parmigiano Reggiano, and milk. Stir in about ¾ of the caramelized onions and season with black pepper and salt.
Add about 1 cup of pasta water to the slow cooker with the chicken. Cook the rigatoni to 50% doneness and add it to the slow cooker.
Serve the pasta topped with the remaining ¼ of the caramelized onions and chopped chives.
