Preheat oven to 375°F.

Cook lentils: Bring 3 cups water, ½ cup lentils, and 1 tsp salt to a boil. Simmer for 15-20 minutes until tender. Strain and set aside.

In a food processor, combine ¼ cup sun-dried tomatoes, ¼ cup walnuts, and 8 oz. white mushrooms. Pulse until finely chopped.

Stir in 1 Tbsp reserved sun-dried tomato oil, 1 Tbsp Italian seasoning, and ½ tsp salt.

In a large bowl, combine the lentil mixture with 14.5 oz. can petite diced tomatoes.

Layering: Spread a thin layer of the lentil mixture on the bottom of a 9x13 inch baking dish. Arrange a layer of 16 oz. lasagna noodles over the mixture.

Spread half of the remaining lentil mixture evenly over the noodles. Add another layer of noodles. Spread the rest of the lentil mixture over the second noodle layer. Top with a final layer of noodles.

Cover the dish tightly with foil. Bake for 25 minutes. Remove foil and bake for another 15-20 minutes, or until bubbly and noodles are tender.