12 oz. fresh mushrooms, sliced
2 1/2 lbs. spaghetti sauce
10 oz. frozen chopped spinach, thawed
2 tbsp. olive oil (or other cooking oil)
1 1/2 lbs. ricotta cheese
1 lb. kielbasa
8 oz. fine grated Mozzarella
2 eggs
1 (6 oz.) can tomato paste
1 lb. Mozzarella cheese
Non stick cooking spray
1 lb. lasagna noodles
1 tsp. basil
Fresh garlic, crushed
Dried hot peppers

Rinse and slice fresh mushrooms, add to sauce and simmer (reserve 2 cups of sauce). Cut kielbasa into pieces at 1/4" x 1/2", brown in a skillet, drain fat and add to sauce. Season sauce to taste with garlic and hot peppers, add the tomato paste to thicken.

While the sauce is simmering; combine the ricotta cheese, eggs, grated Mozzarella, basil and garlic to taste (I use 3 to 4 cloves) in a large bowl. Squeeze all excess water out of thawed spinach and fold into cheese mixture.

Cook the lasagna noodles until partially done, they should be flexible but still chewy (not crunchy). Add the oil to the water while cooking to prevent the noodles sticking together. Drain and return to the pot, cover noodles with cold water.

Spray 9" x 11" x 2 1/2" pan with non stick spray and coat the bottom with a thin layer of the sauce which was reserved. Cover the bottom with a single layer of noodles, overlapping slightly at edges. They can be cut with a knife to make them fit. Spoon in a layer of sauce with mushrooms and kielbasa about 1/2" thick. Add another layer of noodles (lay them at right angles to previous layer) then spoon in a layer of cheese mixture. Continue to alternate layers of meat and cheese separated by noodles until pan is nearly full. Usually this is two layers of sauce with one of cheese depending on thickness of layers and depth of pan; if you use more layers you may need more noodles.

Finish with a final layer of noodles, cover the top of the noodles with the rest of the reserved sauce. Cut the Mozzarella into 1/4" thick slices and lay on top. Cover and bake at 350 degrees until heated through and the cheese is melted, about 1 1/2 hours.