Heat oil in a 5-quart soup pot over medium-high heat; add onion and saute 4 minutes, until translucent. Crumble beef into pot and cook, stirring for 4 minutes or until no longer pink. Stir in chili powder and cumin; cook, stirring, for 2 minutes.
Add milk and broth, then stir in condensed soup until dissolved; bring to a boil, reduce heat to low, cover, and simmer 3 minutes. Stir in pasta; continue to cook, covered, 5 minutes. Stir in cheese until melted and smooth. Remove from heat; let stand 5 minutes or until pasta is fully cooked.
Ladle soup into bowls and garnish with diced tomato, tortilla chips, and minced chile.