In a shallow bowl, combine shrimp (prawns) with all of the spice ingredients, and rub into the shrimp until evenly coated. Heat a large pan/skillet on medium heat and add the olive oil. Saute the shrimp/prawns and the Asparagus while turning occasionally until the shrimp/prawns and asparagus have started to change colour and are just cooked (about 5 minutes).
Combine the lettuce leaves, avocado, onion slices and basil leaves in a salad bowl. Add the shrimp/prawns and avocado over the top. Drizzle with the dressing.
For the dressing:
Combine the yogurt in a bowl with the lemon pepper, lemon juice (if using), water and salt. Mix well to combine.
Notes
You can use frozen shrimp if you don't have fresh, just make sure to thaw them before cooking.