Curried Chickpea Sandwich

Name: Curried Chickpea Sandwich
Ingredients: two 15-ounce cans chickpeas (garbanzo beans), drained and rinsed; 1 medium celery rib, finely chopped; 2 tablespoons finely chopped shallots; 2 teaspoons finely chopped fresh leaf parsley; 1/2 cup vegan or standard mayonnaise; 1 tablespoon red wine vinegar; 1 teaspoon curry powder; 1/2 teaspoon ground turmeric; fine sea salt and freshly ground black pepper; 1 cup greens (such as iceberg, romaine, or watercress), optional; 1 large ripe tomato, seeded and cut into 1/2-inch dice, optional; 4 whole wheat pitas, tops cut off, optional