Preheat your oven to 375°F (190°C).

Cook the lasagna noodles according to package instructions, then drain and set aside.

In a large skillet, heat some oil and sauté the garlic until fragrant. Add the mushrooms and cook until softened, then stir in the spinach until wilted.

In a bowl, combine ricotta cheese, half of the mozzarella, half of the Parmesan, oregano, salt, and pepper.

Spread a thin layer of heavy cream on the bottom of a baking dish, then layer three lasagna noodles down.

Spread half of the cheese mixture over the noodles, followed by half of the sautéed mushroom and spinach mixture.

Repeat the layering process with another three noodles, remaining cheese mixture, and remaining mushrooms and spinach.

Finish with a final layer of noodles, remaining cream, and the rest of the mozzarella and Parmesan on top.

Cover the baking dish with foil and bake for 25 minutes in the preheated oven. Then, remove the foil and bake for another 15-20 minutes until golden and bubbly.

Let the lasagna sit for 10-15 minutes before slicing and serving.