Cantaloupe,Tomato,Avocado, and Sweet Onion Salad

(makes 8 servings)
4 cups 1-inch cubes of cantaloupe
2 medium tomatoes, coarsely chopped
1 large ripe "Haas "avocado, pitted, peeled, and thinly sliced
1/2 medium sweet onion, minced
juice of 1 large lemon
8 green loose-leaf lettuce leaves, washed and crisped
freshly ground pepper
minced flat-leaf parsley for garnish (optional)
In a large bowl, combine the cantaloupe, tomatoes, avocado, and sweet onion. Drizzle with lemon juice. Toss gently to mix.
Line a large salad bowl with lettuce leaves. Spoon the cantaloupe mixture in the center and season to taste with pepper. Sprinkle parsley on top (if using). Serve at once.