Hidden Veg Beef Lasagna

• 1 large brown onion, cut into wedges
• 3 cloves garlic
• 200 g mushrooms
• 2 carrots, cut into 3 pieces
• 2 zucchini, cut into 3 pieces
• 2 tbsp extra virgin olive oil
• 500 g beef mince
• 1.5 tsp Italian herbs
• 700 g passata
• 400 g tin lentils
• 200 g dried lasagne pasta sheets
• 1 cup shredded cheese