Atomic Tuna Salad

Ingredients

• 2 (5 ounce) cans tuna, drained
• 1/2 head broccoli, finely chopped
• 1/2 head cauliflower, finely chopped
• 1/2 red onion, finely chopped
• 2 stalks celery, finely chopped
• 1 cup fat-free mayonnaise, or to taste
• 4 pita bread rounds