1. Bring a large pot of salted water to a boil over high heat. Cook pasta until just tender, about 8 minutes or as package label directs. Drain.
2. Warm oil in a large skillet over medium-high heat. Add meat and 1/2 tsp. salt. Cook, breaking up chunks with a wooden spoon, until meat loses its pink color, about 5 minutes.
3. Stir in salsa and tomato sauce and bring to a simmer. Stir in pasta and cook until bubbling, about 3 minutes. Stir in cheese and cook, stirring, until cheese has melted, about 1 minute longer. Spoon into bowls, top with avocado and chips, if desired, and serve.