High-Protein Tuna Avocado Salad: 1 can tuna, drained; ½ avocado, diced; ¼ cup chopped cucumber; 1 tbsp plain Greek yogurt; 1 tsp lemon juice; salt and pepper to taste. Flake the tuna in a bowl and add the avocado and cucumber. Mix in Greek yogurt and lemon juice.Season with salt and pepper and stir lightly. Protein: ~22–25 g per serving. Enjoy it on its own, in lettuce wraps, or on whole-grain toast.