Classic Lasagna

• 1 onion
• 1 clove of garlic
• 1 egg
• 450 gr beef (lean ground)
• 240 ml creamed cottage cheese
• 28 gr parmesan cheese (grated)
• 3 gr salt
• 2 gr oregano (dried)
• 1 package lasagna
• 1 package mushrooms (sliced)