Heat oven to 350°F. For the crust: Sift 250g strong plain flour and 1 tsp fine sea salt into a large bowl. Roughly break 250g butter into small chunks, add them to the bowl and rub them in loosely. Pour in about two-thirds of 150ml cold water, mixing until you have a firm rough dough adding extra water if needed.

Spray mini muffin cups with cooking spray. On lightly floured surface, roll out the dough and cut with a round cutter, press in muffin cups. Set aside.

For the Filling: In a saucepan, melt butter over medium heat. Cook onions, stirring occasionally, until tender. Add chopped tomatoes and the spices, mix together. Add spinach and potato; cook 2 minutes. Remove from heat. Add the chopped peppers and mix well. Let it cool completely. Once cool, add the crème fraiche or Feta and mix together.

Spoon the Spinach mixture into dough-lined cups. Bake 30 to 35 minutes or until set. Remove immediately from pans to cooling racks.