Use butternut squash as a delicious alternative to pastry - perfect for a vegetarian dinner party.
Preheat the oven to 200C/400F/Gas 6.
Cut the top section of a butternut squash into four thick slices. Trim the sides of each piece into a square shape.
Place the butternut squash pieces in a roasting tin and drizzle with olive oil. Add the garlic cloves and season with salt and freshly ground black pepper. Place in the oven for about 12-15 minutes, or until the butternut squash is soft but not falling apart.
Meanwhile for the topping, heat the oil in a frying pan, add the onions and cook over a low heat for 20 minutes, or until softened and caramelised.
Add the mushrooms and cook for five minutes.
Add the lemon juice and cook for 2-3 minutes further, or until evaporated. Add the peas, cream and tarragon and cook for a further 5-6 minutes, or until the sauce thickens slightly.
Place a piece of butternut squash on each plate, spoon over the mushrooms and serve with baby watercress.
