Preheat oven to 375°. Brown ground beef and drain grease. Add taco seasoning packet. Add lime juice, chopped onions, tomatoes, olives, and jalapeños to bowl and mix. Coat bottom and sides of fairly large casserole dish with olive oil. Start layering. Beans on bottom, ground beef mixture, onion/tomato/olives/jalapeño mixture, Mexican cheese, add dollops of salsa and sour cream alternating. Pop in oven for 20 minutes, or until cheese is melted and sour cream and salsa is spread out.