Step 2
Heat oil in another skillet over medium-high heat. Saute onion, bell pepper, carrots, celery, and garlic in the oil until onions are soft and slightly translucent, 4 to 6 minutes. Add chili powder, onion powder, garlic powder, celery salt, and red pepper flakes and continue to saute until fragrant, 1 to 2 minutes. Add cooked ground beef, tomato puree, tomato paste, vinegar, molasses, mustard, and brown sugar. Bring to a boil; reduce to a simmer, cover, and let cook while preparing pasta.