Enchilada Tostadas

To prepare enchilada sauce: In a small saucepan, heat oil over medium heat. Stir in flour; cook and stir 1 minute. Stir in chili powder and oregano; cook and stir 30 seconds more. Stir in tomato sauce, water, and salt. Bring to boiling; reduce heat. Simmer, uncovered, 8 to 10 minutes or until slightly thickened, stirring occasionally.

To prepare tostadas: Meanwhile, preheat oven to 400 degrees F. Coat both sides of tortillas with cooking spray and place on two large baking sheets. Bake 8 to 10 minutes or until crisp and golden, turning once and rotating pans halfway through baking.

Coat a 10-inch nonstick skillet with cooking spray; heat over medium-high. Add ground beef; cook until browned. Drain off any fat. Stir in beans, rice, the water, and taco seasoning. Cook until thick and heated through, stirring occasionally.

Spoon 1/2 cup meat mixture onto each tortilla. Drizzle with sauce and top with the remaining ingredients.