Marinated beef with zucchini and mushrooms

Ingredients

• 400 gram beef (e.g. steak)
• 250 gram white button mushrooms
• 1 small zucchini (or half a large one)
• 1 onion
• 3 garlic cloves
• 2 tablespoons herbes de Provence
• about 50 ml soy sauce
• olive oil or other neutral oil
• pepper and salt to taste
• rice, pasta, noodles or potatoes for serving