What you need:
What to do:
1. Put the avocado into a medium bowl and stir in the lime juice. Add the tomato. Red onion, red pepper, mustard seeds, coriander, and olive oil. Add the salt and pepper, and toss well. If you like, you can refrigerate the mixture for a few hours.
2. Create a bed of lettuce leaves on each of four small plates. Spoon the salad onto the beds of lettuce, and serve.