1. Place a rack in upper-middle of oven and heat to 400 degrees. Stir together mayonnaise, shallot, and lemon juice in a medium bowl. Gently fold in tuna, celery, and parsley and season with salt and pepper to taste.
2. Arrange English muffin halves on a baking sheet, cut side up. Bake until toasted, 5 to 7 minutes; remove from oven and preheat broiler.
3. Divide tuna mixture among toasted muffin halves, then top each with a slice of tomato and season with salt and pepper to taste. Top with a slice of cheese and broil until melted and golden in spots, 3 to 5 minutes. Sprinkle with more parsley before serving.
Source: Hannaford fresh Magazine, July - August 2018