Heat the olive oil in a large pot over medium-high heat.
Add the chopped onion and red bell pepper; sauté for about 5 minutes until softened. Move the vegetables to one side of the pot.
Add the ground beef to the cleared space and let it sear for 3 minutes. Break it up and mix with the onions and peppers. Cook for another 2 minutes until nearly browned.
Stir in the minced garlic and cook for 30 seconds.
Add chili powder, cumin, and smoked paprika; stir and cook for 1 minute to release the flavor of the spices.
Add crushed tomatoes, chicken broth, and diced green chilies. Stir in the macaroni and kidney beans. Season with salt and pepper.
Bring the mixture to a simmer, reduce the heat to low, and cook uncovered for 12–15 minutes, stirring occasionally, until the pasta is tender.
Remove from heat and stir in the half and half and shredded cheddar cheese until smooth and creamy. Add additional broth if a thinner consistency is desired.
Serve hot, topped with green onions, sour cream, diced tomatoes, cayenne pepper, or extra cheese, if desired.
Notes
Makes about 10 cups.
Adjust spice level using mild or hot green chilies; add cayenne for extra heat.
Store leftovers in an airtight container in the fridge for up to 3 days.