Easy nut roast

Name: Easy nut roast
Prep time: 30 min
Cook time: 2 h
Total time: 2 h 30 min
Cuisine: British
Ingredients: butter, for greasing and frying; 2 tbsp oil; 1 onion, chopped; 3 garlic cloves, grated; 1 tsp finely chopped rosemary (or ½ tsp dried rosemary); 300g/10½oz flat or portabello mushrooms, roughly chopped; 300g10½oz mixed nuts; 75g/2½oz gruyère, grated; 50g/1¾oz vegetarian Parmesan-style cheese, grated; 125g/4½oz cooked mixed grains, (quinoa, wheatberries, barley, etc., from a vacuum pack); 125g/4½oz cooked Puy lentils (tinned or vacuum packed is fine); small bunch thyme, leaves picked; small bunch sage, leaves chopped, plus extra whole leaves for garnish; 75g/2½oz soft breadcrumbs, plus extra for garnish; 40g/1½oz pine nuts (optional); 100g/3½oz dried apricots, chopped; 1 unwaxed lemon, finely grated zest only; 6 large eggs, beaten; 100ml/3½fl oz white wine; 2 tbsp soy sauce; 2 leeks, thinly sliced; salt and freshly ground black pepper, to taste