Cook pasta in 6-8 quarts of rapidly boiling water until al dente (about 5-8 minutes) Rinse with cold water

While pasta is cooking in a heavy saucepan cook onions and garlic in olive oil over medium high heat. Add beans and enchilada sauce, simmer gently, stirring occasionally until thickened, about 6 minutes. Remove from heat and stir in sour cream and salt to taste

In a large serving bowl add pasta. Pour sauce over the top. Add cheese, scallions, cilantro, green olives and avocado. Mix well.

Serve at room temperature

Serves 4-6.