Cook the macaroni according to package directions. Drain and set aside.

In a skillet, add in ground beef and stir often to break it up. Cook for about 4 minutes and then add onions and green pepper. Continue to cook until softened, about 5 minutes. Add in garlic and chili powder and stir to combine.

In the saucepan with the macaroni, stir in diced tomatoes, tomato soup, water, and kidney beans. Add in ground beef mixture and stir to combine. Season with salt and pepper, to taste.

Heat over medium-low heat until macaroni is heated and serve hot.