Preheat oven to 190C.

Grill ground beef on grill pan until brown.

Cut zucchini in half, take out the middle of it and fill it with beef and quinoa. (Quinoa is cooked 1 cup quinoa and 3 cups water, for about 20 minutes)

Place zucchini on baking sheet, and add mushrooms (you can fill them with something too).

Put some olive oil and salt on both zucchini and mushrooms, and close zucchini with tomato slices.

Bake around 45 minutes.

When it's done, dress zucchini with any kind of salad and serve!