In a large pot of boiling salted water, cook pasta according to package instructions; drain well.

Heat olive oil in a large stockpot or Dutch oven over medium heat. Add garlic and onion, and cook, stirring frequently, until onions have become translucent, about 2-3 minutes. Stir in chicken stock, crushed tomatoes, green chiles, chili powder, cumin, oregano and cayenne pepper; season with salt and pepper, to taste.

Reduce heat to low; simmer, covered, until thickened, about 15 minutes. Stir in pasta, chicken, corn, cilantro and lime juice until heated through, about 2 minutes.

Serve immediately, garnished with avocado, tortilla strips, cheese or sour cream if desired.