Preheat oven to 180*C fan.
Mix all the ingredients with an electric mixer, with the hook, until you have a nice dough. If it’s very soft, place in the fridge to cool it down and harden it, if it’s fine, roll it on a flour dusted worktop, place it in a pie tin, fork it all over and bake it for at least 15 minutes (until crust starts to be golden).
Alternatively, you can do it ahead, up to 1 day. In that case, take it out at least 30 minutes before using it (so its soft enough to be rolled).
In a non sticky frying pan, heat the olive oil with the shallots and garlic and sauté all for 8 to 10 minutes, on medium heat, until colored and softened. Add in the spinach, with the lid on, for 2 minutes until they reduce well.
In a jug, whisk the eggs with the milk, season with the chives and salt and pepper.
Lay the veggies on the crust, pour most of the jug on it, place the slices of Stilton and pour the remaining eggs mix.
Bake in the oven for 30 minutes and serve warm or luke-warm with a green salad.