Herbed Tomato Galette with Parmesan Crust

INGREDIENTS

For the pastry

1 1/2 cups

all-purpose flour (plus more for rolling out pastry)

1/2 cup

unsalted butter (cold and cut into cubes)

1/2 tsp

salt

1/2 cup

freshly grated Parmesan cheese

Zest of 1/2 lemon

1/2 cup

ice water

For the filling

ounces/1 cup gruyere cheese (grated)

12 oz

ripe tomatoes (sliced)

1 tsp

fresh basil (finely chopped)

1 tsp

fresh rosemary (finely chopped)

1/4 tsp

freshly ground black pepper

1 tbsp

olive oil

egg (beaten with 1 teaspoon water)