1. Preheat the oven to 180°C.
2. Mix the softened butter and flour. Add a pinch of salt and the egg yolk. Don’t knead the dough as the butter will melt – just carefully fold until you achieve an even dough.
3. Put the dough in the refrigerator for 30 minutes.
4. Roll the dough it into 4-6 small circles or 1 large one depending on the size of your quiche tin.
5. In a pan melt 15g butter and add spinach. Sauté until the edges of the leaves start to soften. Mix eggs, crème fraiche, salt and pepper with the spinach and add to the quiche tins.
6. Top with tomatoes cut in half and slices of Castello® Creamy Blue to your liking. Bake for 20 minutes at 180°C until the top is slightly golden.