1. Preheat the oven to 425ºF. Line 2 large baking sheets with silicone baking mats or nonstick cooking spray. Put the tortillas on the baking sheets, spread a thin layer of refried beans on each (about 2 tablespoon per tortilla), and top each tortilla with about 1 tablespoon beans, 1 tablespoon avocado, 1 teaspoon corn, 1 teaspoon olives, and 1 tablespoon cheese (we like them best when spread lightly with the refried beans and not overloaded with toppings).
2. Bake them for about 10 minutes until the tortillas get browned and crunchy. (Meanwhile, make the ranch dressing and cut up the vegetables, if you are serving them.) Serve the tostadas immediately.

Do Ahead or Delegate: Slice the olives or sausage if using, and shred the Cheddar cheese if necessary, and refrigerate.

Flavor Booster: Drizzle a little hot sauce, such as Tabasco, or fresh lime juice or sprinkle some crushed red pepper flakes on the tostadas at the table.

Slow Cooker Directions: Avocados are not only heart-healthy, but they're also good for your mood. They are full of monounsaturated fat, which can help provide a mood boost. There are so many ways to enjoy avocados, but one of my favorites is spread ripe avocado onto whole-grain toast with a little lemon juice and sea salt.