In medium saucepan combine peas with enough water to cover. Bring to boiling; reduce heat. Simmer, uncovered, for 7 minutes or until very tender. Drain.
Stir in honey, lemon juice, wasabi paste, garlic, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Cook for 3 minutes. Mash slightly with a potato masher or fork until coarsely mashed. Top with lemon slices and watercress. Makes 6 (1/3-cup) servings.