For the crust: Mix flour and salt. Add the egg, the cold butter, and 2 tbsp cold water. Use your hands to form a smooth dough. Form a disc, wrap in cling film and put it in the fridge for 30 minutes (or longer).
Preheat your oven to 400°F (200°C). Lightly grease a 9"/23cm quiche pan or pie dish.
In a large bowl mix eggs, pine nuts, thawed and drained spinach, heavy whipping cream, and crumbled feta cheese together. Season with salt, pepper, and nutmeg to taste.
On a floured work surface, roll out the chilled shortcrust dough until you have a circle that is slightly larger than your quiche pan.
Line your pan with the dough then prick the bottom with a fork a few times and sprinkle the breadcrumbs on top.
Pour the mixture over your crust and distribute well. Then gently press the whole cherry tomatoes into the filling.
Carefully transfer to the oven and bake for 50 minutes or until the top is golden brown and the filling is set. If your quiche gets dark quickly, cover with aluminum foil.
Remove the quiche from the oven and let it rest for 10 minutes before serving.
If you have leftovers and want to reheat the quiche, put it in the oven for a few minutes. That way the crust gets crispier!