In large skillet, heat oil over medium-high heat. When small piece of tortilla sizzles immediately on contact, begin frying tortillas, one at a time, turning once, until golden brown and crispy. Remove from oil and drain on paper towels; cool.
In small bowl combine refried beans and ¼ cup ranchero sauce; set aside.
In medium microwaveable bowl, combine torn chicken and remaining ranchero sauce (saving 2 tablespoons for sauce). Microwave (HIGH) 1-2 minute or until heated through; set aside and keep warm.
Spread each tortilla with an equal amount of refried beans and sprinkle with ½ cup cheese. Place on baking sheet and broil until cheese is melted and bubbly (about 3-5 minutes); remove from oven.
Top tostadas with chicken mixture, lettuce and tomatoes; drizzle with Cumin-Lime Sauce.