Baked Onions with a Creamy Mushroom and Tarragon Filling

Ingredients

• 2 small-medium brown onions
• 2 small-medium red onions
• 1 tbsp olive oil
• 200g chestnut mushrooms
• 1 garlic clove, crushed
• 5g tarragon, chopped
• 40ml vegetarian white wine or vegetable stock
• 75g crème fraîche
• 300g spinach
• 2 tsp butter
• salt and pepper, for seasoning

Method

1. Heat the oven to 180°C/gas mark 4.
2. Trim the root hairs from the base of the 4 onions so they sit upright. Leave the onions with their skins on. Make a lid by slicing horizontally through the onions about 1cm down from the top. Replace the lids, wrap each onion individually with foil, place on a baking tray and roast for 1 hour or until tender when pressed lightly through the foil. Leave until cool enough to handle.
3. Heat the oil in a frying pan and fry the mushrooms on a medium high heat for 10 minutes until they are starting to turn golden. Stir in the garlic, fry for another minute until smelling fragrant, then stir in the tarragon and white wine or vegetable stock. Cook until most of the liquid has evaporated, then stir in the crème fraîche with the seasoning. Simmer for 5-6 minutes until the sauce coats the mushrooms, and it thickens into a creamy consistency filling. Leave to cool.
4. Scoop out the middle of the onions using a teaspoon, leaving the largest 3-4 layers and the papery outer shells intact, making a hollow in the middle. Reserve the remaining onion middles for another recipe (these can be used up in soups and stuffing). Using a teaspoon, stuff the mushroom filling into the middle of the onions and put the lids back on. You can keep the onions chilled for up to 2 days if you don’t want to use them straight away.
5. Heat the oven to 180°C/gas mark 4. Bake the onions for another 25-30 minutes, uncovered on a baking tray, until piping hot throughout.
6. Steam the spinach in a steamer until wilted or blanch by bringing a large pan of water to the boil and putting the spinach leaves in it for 30 seconds until wilted. Transfer to a small bowl and stir in the butter and some seasoning. Serve the onions with the wilted spinach.