Preheat oven to 400 degrees. Grease 24 miniature muffin cups with a little of the oil. Using a round 2 1/2-inch to 3-inch round cookie cutter and cut two rounds out of each tortilla. Lay 1 tortilla round on a smooth, flat surface. Brush, lightly, with a little more of the oil. Fit one tortilla round, oiled side up, into each of the prepared muffin cups. Bake until tortillas are lightly browned and crispy, about 6-8 minutes. Remove from oven and cool in pan for 10 minutes. Remove tortilla cups, transfer to a rack and cool completely. Heat 2 tbsp. of oil in a large frying pan set over medium-high heat. Add onion and garlic; sauté until vegetables are very tender, about 6-8 minutes. Add beef, breaking up with the back of a fork, and cook until beef is brown and cooked through, about 4-6 minutes. Add chili powder and 2 tbsp. cilantro, stirring to blend. Add beans, corn and tomato sauce. Cover and cook, stirring occasionally, until mixture is heated through, about 6-8 minutes. Stir in remaining cilantro, salt and pepper. Fill each tortilla cup with some of the beef mixture. Set bowls of sour cream and cheese in the center of a large serving platter. Arrange tortilla cups around bowls. Serve immediately.

Searching for salty snacks that won't break the calorie bank? Check out these 10 alternatives.