Preheat the oven to 400ºF. Arrange the tostadas on a baking sheet. Spread about ¼ cup refried beans on each tostada shell.
In a bowl, combine the dressing and chicken, and stir until thoroughly coated. Divide the mixture evenly between each tostada shell. Sprinkle with cheese and garnish with tomatoes and green onions, if using.
Bake for 5 minutes or until cheese is melted and bubbly. Serve immediately.
For safe meat preparation, reference the USDA website.
For dips, make and enjoy your dip creation. Then, refrigerate within 2 hours or discard.