seafood salad recipe

For the salad: 1 lb shrimp, peeled, deveined, and cooked 1 lb lump crab meat 1/2 cup celery, finely chopped 1/2 cup red bell pepper, finely chopped 1/2 cup red onion, finely chopped 1/4 cup fresh parsley, chopped 1 cup cherry tomatoes, halved 1 avocado, diced Mixed greens or lettuce, for serving