1. In a large pot or Dutch oven heat the olive oil over medium-high heat. Add the onion and green bell pepper and cook for about 4 minutes or until the onions are soft and translucent. Add the garlic and cook for about a minute.
2. Add the ground beef to the pot and cook, stirring and breaking up the beef until the meat is no longer pink. If you aren't using lean ground beef, you may need to drain off any excess fat rendered.
3. Add the spices, crushed tomatoes, chili beans and broth. Bring to a simmer and lower the heat to low. Add the pasta and stir. 
4. Cover and simmer for about 10 to 12 minutes or until the pasta is al dente, stirring a few times during the cooking process to make sure the pasta doesn't stick to the bottom of the pot. If the pasta gets too dry, add a bit of water.
5. Turn off the heat and add most of the cheese (about 1 1/2 cups). Stir until the cheese is melted. Serve hot topped with the remaining cheese.

To Make Chili Mac in the Instant Pot/Pressure Cooker

1. Set the Instant Pot to the Sauté Setting and add the oil. When hot, sauté the onion and green bell pepper until soft. Add the garlic and cook for about a minute.
2. Add the ground beef and cook, stirring and breaking up the beef until the meat is no longer pink.
3. Add the spices, crushed tomatoes, chili beans and broth and scrape the bottom of the pot with a wooden spoon to remove any brown bits stuck at the bottom..
4. Cover and seal the pot. Set the valve to seal. Select the "manual" function and cook on high pressure for 5 minutes. Then do a quick release and remove the lid.
5. Stir in most of the cheese (about 1 1/2 cups). Stir until the cheese is melted. Serve hot topped with the remaining cheese.