Whole grain tortilla (8-inch): 1 (45g), Tuna (canned in water, drained): 85g (3 oz), Greek yogurt: 15g (1 tbsp), Dijon mustard: 5g (1 tsp), Apple: 30g (1/4 medium, diced), Celery: 15g (1 stalk, diced), Walnuts: 10g (1 tbsp, chopped), Lemon juice: 5ml (1 tsp), Mixed greens: 15g (1/2 cup), Salt: 1g (pinch), Black pepper: 1g (1/4 tsp)