For the pastry crust:
2 cups (250g/8 1/2 ounces) all-purpose flour
A pinch of sea salt
1/2 cup plus 1 tablespoon (125g/4 1/2 ounces) chilled unsalted butter, cut into small cubes
1/3 cup (75 ml) cold whole milk

For the filling:
1 tablespoon canola or olive oil
4 Little Gem lettuce hearts, trimmed and quartered
Sea salt and freshly ground black pepper
1 tablespoon (15g/1/2 ounce) butter
2 bunches green onions (about 250g/9 ounces), trimmed and cut into chunky slices
3 1/2 ounces (1oog) Lancashire medium cheddar, or hard goats cheese
2 large eggs, plus 2 egg yolks
1 cup (200ml) heavy cream
1 cup (200ml) whole milk

To make the pastry, sift together the flour and salt, or give them a quick blitz in a food processor. Add the butter and rub in with your fingertips, or blitz in the food processor, until the mixture resembles fine bread crumbs. Mix in the cold milk, little by little, until the pastry just comes together, then turn out onto a work surface and knead briefly to bring it into a ball. Wrap and chill for 30 minutes.

Preheat the oven to 350°F / 180°C. On a lightly floured surface, roll out the pastry quite thin and use to line a 10-inch / 25-cm tart pan. Leave the rough edges of the pastry hanging over the sides of the pan.

Line with foil, fill with baking weights, and blind bake for 15 minutes. Remove the foil and weights, prick the pastry in a few places with a sharp fork, and bake uncovered for a further 10 to 15 minutes, or until the pastry is just starting to color. Using a small, sharp knife, trim away the excess pastry from the edge. Leave the oven on.

To make the filling, heat the oil in a frying pan over medium heat. Add the quartered lettuce hearts, sprinkle with salt and pepper, and cook for about 5 minutes, turning once or twice, until the cut surfaces are golden brown. Add the butter toward the end of cooking, letting it melt in the pan, then spooning it over the lettuces. Using a slotted spoon, remove the lettuce hearts and arrange in the tart shell.

Reduce the heat under the frying pan a little. Add the green onions and sauté gently for 5 minutes, then scatter in the tart shell over and around the lettuce hearts. Crumble or grate the cheese over the top.

Lightly beat together the eggs, egg yolks, cream, and milk in a bowl and season generously with salt and pepper. Carefully pour this mixture into the tart shell (depending on the depth of your pan, you might not need all of it). Bake for about 35 minutes until golden. Serve warm or at room temperature.

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