I made these lovely mushroom galettes a little while ago, the recipe below is for one large pie but I made 4 smaller ones instead. I simplified the original recipe as I didn't have time to make caramelised onions but these are still very tasty.
Mushroom Galettes (adapted from Circle B Kitchen)
For the pastry
160g plain flour
1/4 tsp salt
113g cold unsalted butter, cut into pieces
60g plain yogurt or sour cream
2 tsp lemon juice
60 ml cold water
1 onion, thinly sliced
300g mixed mushroom, cleaned and sliced
1 tbsp butter,
1 tbsp oil
1 tbsp chopped fresh herbs (rosemary, sage, thyme)
50g blue cheese, crumbled
salt and pepper
1 9-inch pie crust dough
1 egg, beaten with a little water
Preheat oven to 200C.
Put the flour and salt into a bowl and add in the butter. Using your fingertips rub the butter into the flour until it resembles breadcrumbs.
In a small bowl, stir together the sour cream, lemon juice and water and add this to the flour mixture. Mix in the liquid until you get something that resembles dough. Wrap in clingfilm and put in the fridge for 1 hour.
Put the dried mushrooms into a bowl and cover with boiling water, pushing them down to make sure they’re all submerged. Leave them to soak for about 15 to 20 mins, then drain. Chop the mushrooms and set aside.
Melt the butter and oil in a frying pan over a high heat and add the onion and fresh mushrooms. Sauté the mushrooms until they are softened and any liquid has mostly evaporated. Add the herbs, season and sauté for another 5 mins. There should be no excess liquid in the pan. Leave the onions and mushrooms to cool and mix with the porcini mushrooms.
Line a baking sheet with greaseproof paper. Roll the pie dough out to an 27-30cm circle and place on the lined baking sheet. Place the mushroom mixture in the centre of the dough, leaving a 5cm border all the way around. Fold the pie dough towards the center, overlapping where necessary. The mushrooms should be exposed in the centre. Sprinkle over the blue cheese.
Brush the crust with the beaten egg and sprinkle over a little salt. Place the galette in the oven and bake for 30 mins or until the crust is just golden brown.