Preheat the oven to 400 degrees F. Crumble the tuna into a mixing bowl. Add the onions
, and relish. Mix thoroughly. Season the mixture with salt and pepper. Stir in enough mayonnaise to moisten the salad according to taste. Reseason the salad with salt and pepper. Spread a quarter of the salad over four pieces of bread and place on a baking sheet. Top each salad with a piece of cheese. Place the sheet in the oven and cook for a couple of minutes or until the cheese melts. Season the tomato slices with salt and pepper. Peel
and remove the pit
from the avocado. Slice the avocado into 1/4-inch slices. Season the avocado with salt and pepper. Top the melted cheese with the tomatoes
and remaining slices to toasted bread. Place each sandwich on a plate and cut in half. Garnish
the sandwiches with the Cole slaw, chips, and pickles.