Before you begin, chop the onions and clean the mushrooms with a wet cloth (avoid washing them as they'll absorb water). Grate all the cheese and slice the zucchini lengthwise into thin pieces.

Preheat a pan on the stove and pour olive oil once it's hot.

Add finely chopped onions and sauté until slightly darkened in color. Add beef, continue sautéing, and cut into pieces until fully cooked.

Once cooked, add the mushrooms, salt, and pepper, and sauté a bit more. Add tomato and continue cooking, then pour in stock. Let it boil, lower the heat and continue cooking until all ingredients are combined. Turn off the stove and set aside the mixture in its pan.

Preheat and add cream, cream cheese, grated mozzarella, and grated cheddar in a new pan. Mix until the cheeses melt and integrate with the cream. Set aside the sauce.

Preheat the oven and line a baking tray with parchment paper. Place a layer of finely chopped zucchini pieces at the bottom, covering it completely. Spread some beef mixture over the zucchini, then pour cheese sauce over it without mixing.

Add another layer of zucchini, beef mixture, and cheese sauce. Repeat until all mixtures are used. Sprinkle grated cheese on top of the lasagna and bake for 40 minutes in the preheated oven.