Spaghetti Bolognese (made healthier!)

• 1 tbsp extra virgin olive oil (garlic infused)
• 2 brown onions
• 500 g mushrooms
• 1 red capsicum (pepper)
• 340 g wholemeal spaghetti
• 400 g beef mince
• 420 g tin lentils, drained
• 840 g tins diced tomatoes
• 2 tbsp Italian herbs
• 2 tbsp balsamic vinegar