Cooking with Max Rocha: Potato and Onion Galette

Max Rocha is a London-based chef who has worked at some of London’s finest restaurants, from St John Bread and Wine to The River Café. Over the coming weeks, he will share a series of seasonal recipes to enjoy while restaurants remain shut.

This week’s recipe is for a potato and onion galette. Galette is a free-form tart. I made this for a picnic at the weekend and it went down really well – it’s a very rustic dish and not too hard to make. If you are intimidated by making your own pastry, you can buy perfectly good short crust pastry in the supermarket. I like to serve this tart at room temperature with a green salad.

Potato and Onion Galette

Pastry

125 grams plain white flour
Ten grams wholewheat flour
Pinch of salt
55 grams butter, cubed and cold
Three tablespoons cold water
Two eggs for egg wash

1. Place flour and salt in a bowl and add the cold cubes of butter.
2. Use your fingertips to rub the flour until you have a mixture that is like breadcrumbs. Work as quick as you can so it doesn’t become greasy.
3. Add the cold water and form into a dough.
4. Wrap dough in cling film and chill for at least 30 minutes before using.

Filling

Four large potatoes, peeled and thinly sliced on a mandoline
Two large white onions
50 grams butter
Small bunch of thyme
Salt and pepper

1. Parboil slices of potato in salted water until just soft. When drained, add some olive oil so they don’t stick together.
2. Slice onions at the same thickness as potatoes, sweat in butter and oil on a low heat in a heavy-bottom pan until very soft and sweet. You don’t want any colour on them. Season with salt, pepper and thyme. Should take around 40 minutes or so.

To assemble and cook

1. Preheat the oven to 220 degrees.
2. Roll out pastry into a circle the size you want the galette and place on parchment paper.
3. Lay down a single layer of potatoes, then onions, then a final layer or potatoes, seasoning each layer as you go.
4. Fold over the edges of the galette to form the crust. Simple small folds. It doesn’t need to be perfect.
5. Whisk two eggs with a drop of milk and egg wash the sides with a brush.
6. Sprinkle salt, pepper and fresh thyme over the top of the tart and place the tart (still on the parchment paper) on an oven tray and bake for 40 minutes or until crusts are golden brown and potatoes are totally cooked.
7. Allow to cool on a wire rack before eating.