• 675 g/1½ lb shallots
• 2 tablespoons olive oil
• 1 bunch spring onions
• 1 large egg
• 2 egg yolks
• 150 ml/¼ pint crème fraîche or double cream
• 2 teaspoons caster sugar
• salt
• black pepper

For the pastry

• 100 g/4 oz plain flour
• 100 g/4 oz semolina
• 1 teaspoon salt
• 100 g/4 oz butter
• 1 tablespoon water

To make the pastry, put the flour, semolina and salt into a bowl and stir to mix. Gently melt the butter with the water in a small saucepan, then pour the hot liquid on to the flour, stirring it with a wooden spoon until you have a warm dough. Take bits of the dough and press them evenly over the bottom and up the sides of a 24-25 cm/9½-10 in loose-based fluted flan tin, bringing the edge slightly up above the rim. Refrigerate while you prepare the filling.

Peel the shallots and slice them across in fairly thin rings. Put the olive oil into a large, heavy-based frying pan over a medium heat, add the shallots and cook, stirring often, for about 15 minutes or until really soft — if they begin to brown, reduce the heat. Leave on one side to cool a bit.

Preheat the oven to 220°C/425°F/gas mark 7. Trim the spring onions and slice across at 5mm/¼in intervals, using as much of the green part as possible. Whisk the egg and egg yolks together in a mixing bowl and then whisk in the cream. Season with salt and plenty of black pepper. Stir the cooled shallots and the spring onions into the egg and cream mixture and pour into the chilled pastry case. Level the surface and sprinkle with the caster sugar. Cook the tart towards the top of the oven for about 25 minutes, until it is just set in the middle and small specks of black have appeared on the surface.

Put the flan tin on top of a tin or jar, push the crumbly tart carefully up out of the rim of the tin and ease on to a serving plate with a spatula.