Wisconsin Milk Marketing Board, Inc.
I like using whole-wheat lasagna noodles for this recipe because they do not get mushy like white pasta tends to do in the slow cooker. The noodles do not need to be oven-ready noodles.
Heat skillet over medium high heat; add ground beef. Use a wooden spoon to break the meat into even pieces. Add taco seasoning and tomato paste, stirring occasionally for even browning. Continue to brown the beef until you no longer see pink; drain the excess fat. Set aside.
Place ricotta in medium bowl; add the egg and whisk until combined. Set aside.
In casserole, slow cooker, or 6-quart oval slow cooker, layer 5 uncooked whole-wheat lasagna noodles on the bottom of the pan (you may break some noodles in half to fit slow cooker shape). Spoon half of ricotta mixture over noodles as evenly as possible. Sprinkle half of beef over ricotta. Pour half of salsa over beef.
Mix queso quesadilla, queso blanco, cheddar and cotija to blend. Sprinkle half of cheese mixture over salsa.
Repeat layering, starting with remaining lasagna noodles and ending with remaining cheese mixture.
Top cheese layer with sliced olives, if using. Cover slow cooker; cook on high 2 to 3 hours or low about 4 hours. Serve lasagna immediately with favorite toppings (sour cream, red onion, cilantro and avocado are my favorites.).