Sea Spinach and mushroom tart (left) and tomato tart / Jason Lowe
Serves 4

I've used sea spinach here, but if you can't get it, use baby spinach.

4 butter puff pastry rectangles rolled to 3-4mm and cut to about 8x10cm
2 handfuls of small sea spinach or baby spinach leaves, washed and dried
100-120g button or oyster mushrooms, sliced
A couple of knobs of butter
Salt and freshly ground black pepper
100ml double cream
50g grated Cheddar
Crumb topping (optional)

Preheat the oven to 200C/gas mark 6. Dock the pastry with a fork to prevent it rising, place on a baking tray and bake for 5 minutes, then remove from the oven.

Melt the butter in a pan and gently cook the mushrooms for 3-4 minutes, seasoning and stirring as they cook; stir in the spinach and cook for about a minute.

While the spinach and mushrooms are cooking, simmer the cream until it's reduced by two-thirds and thickened, stir in the cheese until it's melted; remove from the heat, transfer to a plate with some kitchen paper to absorb any juices, and leave to cool.

Spread the cheese mixture on the tarts, then spoon the spinach mixture on top. Bake for about 5-6 minutes, covering the spinach with foil so that it doesn't discolour.

Serve immediately.