In a large skillet, heat 2 tablespoons (30 ml / 1 fl oz) of oil over medium heat.
Add the minced garlic and diced onions, and sauté for about 10 minutes until the onions are soft and translucent.
Stir in the drained beans and water.
Bring to a simmer and cook for 5 minutes.
Using the back of a spoon, gently mash about half of the beans directly in the pan to create a creamy texture.
Stir to combine and keep the mixture warm over low heat.
Position an oven rack near the top and preheat the broiler.
Brush both sides of each tortilla with the remaining 3 tablespoons (45 ml / 1.5 fl oz) of oil.
Arrange them in a single layer on a baking sheet (you may need to work in batches).
Broil the tortillas for 1-2 minutes per side, or until lightly golden and crisp. Watch them closely as they can burn quickly!
Spread an equal amount of the warm bean mixture onto each crisped tortilla.
Sprinkle generously with the grated Monterey Jack cheese.
Return the baking sheet to the broiler and broil for another 2-3 minutes, or until the cheese is completely melted and bubbly.
Remove from the oven and top each tostada with a dollop of sour cream.
Serve immediately with your favorite salsa and toppings.
Don't be shy with toppings!
Sliced avocado, shredded lettuce, fresh cilantro, pickled jalapeños, or crumbled fried tofu add fantastic flavor and texture.
