Butternut squash, spinach and goat cheese tart

Update: I forgot that I added an onion! Revised recipe below.

I made this a few weeks ago, when I had some friends over for brunch. The brunch was an excuse to eat homemade doughnuts, but I thought I had better serve something a bit more substantial first. I wanted to use butternut squash, as a huge one had taken over all my (very limited) counter space, and I found this recipe, but it had been adapted from a book called Roast Figs, Sugar Snow by Diana Henry. I haven't got my hands on this book yet, but it sounds good--wintry recipes from all over the world. I used goat cheese, as I didn't have any blue cheese on hand, but I plan to make it with the stronger cheese next time. I thought this tart was fantastic--very flavourful and it made excellent lunches for me for a few days. Just eat any leftovers at room temperature, as microwaving destroys the crust. I used an all-butter crust instead of the shortening one (eeww), but used a lower ratio of butter to flour, as it was all I had. It was perfect--buttery and flaky.

Pastry

1½ cups all-purpose flour

½ teaspoon salt

8 tablespoons unsalted butter, cubed and frozen

ice water, 4-8 tablespoons (mine took 7)

Combine flour and salt in food processor and pulse to mix. Add butter, and pulse until butter is broken up--some pieces will be tiny, but some should still be pea-sized. Add water a few tablespoons at a time and pulse. You don't want it to come together in a ball. Instead, open the processor and squeeze some of the mixture together. If it holds, you're done. I often put too much water in my impatience, but it'll be fine after resting. Flatten into a disc, wrap in plastic and refigerate for a few hours.

Preheat oven to 350℉. Roll out dough on a lightly floured surface till it is about 13" in diameter. It'll be thin, which is how I like my crust. Transfer to a 10" tart pan or springform pan (I used a springform). If using a tart pan, you can fold down the pastry to make a thicker edge. If using a springform, trim the pastry so it is an even(ish) height all around. Freeze while the oven preheats. I baked the squash at the same time, so read below to have that ready. Prick the pastry with a fork, line it with greased foil and dried beans. Bake for about 10 minutes, then remove the foil and beans and bake for another 10 minutes or so. You want it set and dry, but only lightly coloured. My oven runs very slow, so keep an eye on it! Cool on a rack.

Filling

1 pound (454 grams) of butternut squash
olive oil
1 large onion, thinly sliced

½ pound (250 grams) of spinach, washed and stemmed

2 large eggs, plus one yolk

1 cup whipping cream

2 ounces (about 50 grams) grated Parmesan cheese

3.5 ounces (100 grams) goat cheese, crumbled into large pieces

a few leaves of fresh sage, minced, or a grating of fresh nutmeg
salt and pepper

Cut squash into large cubes (about 1"/2.5 cm) and toss with a bit of olive oil, salt and pepper on a baking sheet. Roast in the oven, underneath the tart shell if you're doing both, for 25 minutes or so, till tender. Set aside to cool.
Saute onion in olive oil until it is completely softened and nicely brown.
Blanch spinach in boiling water for a minute, drain, rinse with cold water, then squeeze till it's dry. Chop roughly. 

Mix the eggs and yolk, cream, Parmesan, sage or nutmeg, and salt and pepper to taste.

Scatter the squash, spinach and goat cheese over the bottom of the tart shell, and pour the custard mixture over. It will be very close to the top of the crust, and that's fine. Bake at 350℉ for 40 minutes, until golden and set. Let cool on a rack for at least 10 minutes before removing from pan and serving. This tart is good warm or at room temperature.