Easy, Healthy, and Delicious Kids' Tuna Melt

1. Prepare the tuna mixture: In a bowl, combine 1 can of wild tuna (drained), half a diced purple onion, two diced celery sticks, diced pickles, mayonnaise, a splash of lemon juice, and season with salt and black pepper to taste. Mix everything well.
2. Assemble the sandwich: Take slices of organic sourdough bread. Spread a generous amount of the prepared tuna mixture onto one slice of bread.
3. Top the tuna mixture with slices of tomato and a slice or sprinkle of cheddar cheese.
4. Toast the sandwich until the bread is golden brown and the cheese is melted and bubbly. Serve immediately.