Mediterranean Tuna Salad in a Pita Bowl

Name: Mediterranean Tuna Salad in a Pita Bowl
Ingredients: 1 cup white rice; 1 3/4 cups water; 1/4 cup chopped cilantro; Juice from 1 whole lemon; 4 pita bread rounds; 1 1/2 tablespoon extra-virgin olive oil; 1 small white onion, chopped; 2 teaspoons lemon juice; 1 small garlic clove, chopped; 1/4 teaspoon Dijon mustard; Salt and pepper to taste; 1 can (7 oz.) white tuna, drained and flaked with a fork; 1 Roma tomato, seeded and diced; 1/4 cup kalamata olives,pitted and chopped; 1 cup fresh spinach leaves