In a large skillet, cook beef over medium heat until no longer pink; drain. Add in chopped onion and 2-3 cloves minced garlic. Stir in rice, taco seasoning and water. Bring to a boil. Reduce heat; simmer, uncovered, for 5 minutes. Stir in rice. Cook and stir until liquid is evaporated. Add refried beans, cottage cheese, and 1 cup shredded cheese to beef mixture and stir until well mixed.
Spread about 1/2 cup filling into each flour tortilla, and roll up. Place seam side down in two greased 13-in. x 9-in. x 2-in. baking dishes.
Combine enchilada sauce and sour cream; pour down the center of enchiladas. Sprinkle with remaining cheese. Bake one casserole, uncovered, at 350 degrees F for 20-25 minutes or until heated through and cheese is melted. Cover and freeze remaining casserole for up to 3 months.
To cook frozen casserole, let thaw in refrigerator overnight. Add 5-10 minutes to baking time.