30g |
butter, plus extra for the dish and to bake |
1 |
small onion, finely chopped |
1 |
garlic clove, chopped, plus 1 clove for the dish |
200g |
small waxy potatoes, peeled and sliced 5mm thick |
150ml |
double cream |
100g |
chestnut mushrooms, halved and thinly sliced |
|
salt |
|
freshly ground black pepper |
50g |
hard, mature cheese such as gruyere or cheddar, grated |