1/4 cup fresh lime juice
1/2 cup chopped fresh cilantro
1 teaspoon sugar
1 tablespoon chili powder
1/4 teaspoon ground cumin
1/2 teaspoon salt
1/4 teaspoon black pepper
1/2 cup olive oil
1 medium onion, chopped
3 garlic cloves, finely chopped
1 to 2 fresh serrano chiles (including seeds), finely chopped
1 tablespoon chili powder
2 teaspoons ground cumin
2 tablespoons olive oil
1 1/2 lb ground chuck
1 (8-oz) can tomato sauce
1/2 teaspoon salt
1/4 teaspoon black pepper
1 (1/2-lb) firm-ripe California avocado
1 head iceberg lettuce, thinly sliced (8 cups)
1 large tomato (1/2 lb), chopped
1/4 lb coarsely grated extra-sharp Cheddar (1 1/2 cups)
1 (15- to 19-oz) can black beans, drained and rinsed
1 (6-oz) can sliced pitted California black olives, drained
Accompaniment: tortilla chips