taco shells, to serve • OPTIONAL: 500 grams minced beef • tomatoes, chopped, to serve • iceberg lettuce, shredded, to serve • Spanish Onion, fresh, chopped • (1 1/2 cups) grated cheddar cheese, to serve • Sour cream (optional), to serve • Avocado or Guacamole • Lime • (3/4 cup) long-grain white rice • olive oil • brown onion, finely chopped •