sea salt and freshly ground black pepper,
1/2 cup (4 fl oz / 125ml) vegetable stock
1/4 cup (2 fl oz / 60ml) dry white wine
1 tbsp butter, chopped
oven to 350F (180C / Gas 4). Using a sharp knife, cut a thin slice
from bottom of each onion, so that it stands steady. Using a
teaspoon, scoop out inside of each onion, leaving a 1/4-inch (6-mm)
shell. Finely chop scooped-out onion flesh. Reserve 2 tbsp chopped
onion and set aside. Save the remainder for another use.
Place onion shells in a large saucepan and
cover with cold water. Bring water to boil over medium heat, then remove
from heat. Drain onions and place upside down on a wire rack.
Melt butter in a frying pan over medium
heat. Add reserved chopped onion and garlic and cook until onion softens,
about 2 minutes. Add mushrooms and stir gently until mushrooms soften,
about 3 minutes. Remove from heat and add breadcrumbs, parsley, thyme and
salt and pepper to taste. Allow mixture to cool slightly.
Spoon seasoning into onion shells, pressing
it in firmly. Place onion shells in a lightly oiled baking dish just large
enough to hold them. Combine stock and wine in a measuring cup and pour
around onions. Top with chopped butter. Bake until onions are tender,