Preheat the oven to 500 degrees . In a small bowl, stir together the ham, cheese, mayonnaise, onion, chili sauce and mustard.
Arrange the bread slices on a foil-lined baking sheet. Place 2 pickle slices on each slice of bread, then spread about 1 tablespoon of the ham mixture on top. Bake the toasties for 8 to 10 minutes, until golden and bubbly. Cool for a few minutes before serving.