Step 1

Whisk together lime juice, cilantro, sugar, chili powder, cumin, salt, and pepper, then add oil in a stream, whisking until emulsified.

Step 2

Cook onion, garlic, chiles to taste, chili powder, and cumin in oil in a 12-inch heavy skillet over moderate heat, stirring occasionally, until onion is well softened, about 6 minutes. Add beef and cook, stirring occasionally and breaking up lumps, until meat is no longer pink, about 5 minutes, then spoon off any excess fat from skillet.

Step 3

Add tomato sauce, salt, and pepper to beef and cook, stirring, until slightly thickened, about 3 minutes. Remove from heat.

Step 4

Peel and pit avocado, then cut into 1/2-inch pieces.

Step 5

Spread lettuce over bottom of a shallow 4-quart dish. Spoon beef mixture evenly over lettuce and continue making layers with tomatoes, cheese, beans, avocado, and olives. Drizzle dressing over salad.