An irresistible Veggie mushroom burger filled with melty mozzarella and slathered in homemade tomato relish. This is designed to be a low-cost recipe Ingredients For the relish 1 tbsp olive oil 1 onion, finely diced salt and pepper 1 garlic clove, crushed 200g/7oz tinned tomatoes 1 tbsp white wine vinegar For the onions 25g/1oz butter […]