Nut roast

Name: Nut roast
Prep time: 30 min
Cook time: 1 h 5 min
Total time: 1 h 35 min
Cuisine: British
Ingredients: 1 tbsp olive oil; 15g butter; 1 large onion, finely chopped; 2 sticks celery, finely chopped; 2 garlic cloves, finely chopped; 200g chestnut mushrooms, finely chopped; 1 red pepper, halved, deseeded and finely diced; 1 large carrot, grated; 1 tsp dried oregano; 1 tsp smoked paprika; 100g red lentils; 2 tbsp tomato purée; 300ml vegetable stock; 100g fresh breadcrumbs; 150g mixed nuts such as walnuts, pecans, hazelnuts and Brazil nuts, roughly chopped; 3 large eggs, lightly beaten; 100g mature cheddar, grated; handful flat-leaf parsley, finely chopped; 2 tbsp extra virgin olive oil; 2 garlic cloves, finely sliced; 1 sprig rosemary; 400ml passata