Wasabi Tuna Pitas

Ingredients

• 1 (6-ounce) can solid white tuna in water, drained
• 2 tablespoons light mayonnaise
• 2 tablespoons sweet pickle relish
• 2 tablespoons finely chopped red onion
• 1/2 teaspoon wasabi powder (dried Japanese horseradish)
• 2 (6-inch) whole wheat pitas, cut in half
• 4 red leaf lettuce leaves
• 4 (1/4-inch-thick) slices tomato (about 1 medium)