Shop-bought, ready-rolled puff pastry comes into its own here: cut into circles as desired. If you're feeling impatient, make one large tart by transferring the entire sheet of pastry onto a baking tray, scoring the border as described, then spreading the mushroom filling within it. You won't get the extra-crispy edges of the individual tarts, but it will be equally delicious.
2 tbsp olive oil
2 tbsp butter
1 large onion (about 200g), cut into 2-3cm dice
500g mixed mushrooms*, sliced or roughly torn
1½ tsp salt
2 tsp thyme leaves
2 garlic cloves, finely chopped
½ tsp freshly ground black pepper
1 tsp lemon juice
2 tbsp dill**, roughly chopped, plus extra for garnish
150g ricotta cheese
100g gruyere or cheddar cheese, grated
1 packet (375g) ready-rolled, butter puff pastry
1 egg, lightly beaten, for egg-wash
1. Heat half the olive oil and half the butter in a large frying pan and cook the onion over medium heat for 5 minutes until softened. Add the mushroom, remaining oil and butter, salt and thyme. Cook on high for about 10 minutes, stirring occasionally; the mushrooms will exude a lot of moisture to begin with, most of which will eventually evaporate. As the mushrooms begin to brown a little (when the liquid has mostly evaporated), add the garlic and pepper. Stir for a minute, then remove from heat and add the lemon juice and dill. Set aside to cool for 30 minutes, then fold in the ricotta and gruyere (or cheddar).
2. Unroll the puff pastry and cut to your desired shape: there's enough filling for 6 individual tarts (about 12cm diameter each). Using a small, sharp knife, lightly score a 1cm border around the edge of each circle of pastry: this will create a slightly raised edge to keep the filling in. Place the pastry rounds on trays lined with baking paper – you can use the baking paper that comes with the puff pastry – and then carefully spoon mushroom filling onto the middle of each tart. Spread the filling out with the back of a spoon so it's evenly distributed, ensuring that it stays within the scored borders.
3. Using a small pastry brush, paint the border lightly with the egg wash, then place the tarts in the fridge to chill.
4. Heat the oven to 185C fan-forced (205C conventional). When it reaches this temperature, place the tarts onto the upper third rack in the oven. Bake for 25-30 minutes or until the pastry is golden brown. Lift up the edge of one of the tarts to peek underneath: the bottom should be cooked through and lightly golden in colour. If not, return to the oven for a few more minutes.
5. Scatter the extra dill on top of the tarts and serve warm with a green salad.
*Use any combination of mushrooms for this flavourful tart, slicing or even tearing them before cooking to produce different textures.
**Grassy, assertive dill cuts through the richness of the cheese and buttery pastry, but parsley or tarragon works just as well.
Find more of Helen Goh's recipes in the Good Food New Classics cookbook.