Heat the oven to 200C (180C fan)/gas 6. On a floured surface, roll out the pastry so that it fits a 25-27cm quiche or tart dish. Gently line the dish, pushing the pastry into the sides, allowing any excess to hang over the edge.
Prick all over with a fork, line with baking paper or foil, fill with baking beans or rice, and bake for 25 minutes. Once golden, remove the paper or foil and the beans, and bake for another five minutes. Set aside to cool.
Meanwhile, bring a pan of salted water to a boil, blanch the broccoli for two minutes, then drain and leave to steam dry.
Whisk the milk, creme fraiche and eggs vigorously, until frothy. Strip the thyme leaves from their branches, add to the eggs and season well.
Turn down the oven to 180C (160C fan)/gas 4. Once the tart case is cool, trim any excess pastry, then lay in the cooled broccoli in an even layer. Dot teaspoons of the gorgonzola around the broccoli.
Put the tart on to a tray to catch any overflow, then carefully pour over the egg mix so it comes right up to the brim, adding a splash more milk, if necessary.
Bake in the middle of the oven for 35-40 minutes, until golden and just set in the middle. Remove, leave to cool, then serve with a green salad.