Vegetarian sausage rolls

Step 1: Heat 2 tbsp olive oil in a large frying pan over a medium heat. Fry 1 onion for 5 minutes until soft, then add 2 cloves garlic for 1 minute.

Step 2: Turn the heat to high, add 10 ½ oz chestnut mushrooms and cook, stirring, for 8–10 minutes. They'll release water, then it evaporates and they start to sizzle and brown. A common mistake is stopping while the pan is still wet: the filling must be dry, or the pastry turns soggy.

Step 3: Stir in 1 carrot, 1 tsp dried sage, ½ tsp dried thyme, 1 tbsp soy sauce and 1 tbsp tomato paste and cook for 2 minutes until sticky. Tip into a bowl and cool for 10 minutes.

Step 4: Add 14 oz tinned brown lentils and mash roughly with a fork, leaving some whole. Stir in 2 ½ oz dried breadcrumbs, 2 ⅛ oz mature cheddar (vegetarian rennet), ½ tsp salt, ¾ tsp black pepper and half the ½ egg. The mixture should hold firmly when squeezed. (For the meat version, use 500 g seasoned raw pork or beef sausage mince instead of this filling.)

Step 5: Heat the oven to 400°F (375°F fan) and line two trays with baking paper. Cut each sheet of 1 ⅜ lb ready-rolled puff pastry in half lengthways to make 4 long strips.

Step 6: Spoon a quarter of the filling along each strip, shaping it into a firm log about 3 cm thick, slightly off-centre. Brush the far edge with the remaining ½ egg, fold the pastry over and press the seam with a fork. Chill for 10 minutes to firm.

Step 7: Cut each log into 4–6 pieces, set seam-side down on the trays and snip two small slits in each top. Brush with egg and sprinkle with 1 tbsp sesame seeds.

Step 8: Bake for 22–25 minutes, until puffed and deep golden, with the layers crisp and flaky at the sides.

Step 9: Cool for 5 minutes and serve warm with 6 tbsp tomato sauce (ketchup). They reheat well in a hot oven for 8 minutes.