Sift the flour and mix with the dry yeast. Make a well in the middle.
Add the lightly beaten eggs, a pinch of salt, and cream and knead.
Gradually add the (warm) milk until you get a homogeneous dough, soft but not sticky.
Add a tablespoon of oil and knead a little more until smooth.
Leave the dough to rise for an hour in a warm place, away from drafts.
In the meantime, prepare the filling.
Boil the unpeeled sweet potato for 15-20 minutes, until a fork goes in easily.
Remove and put on a plate to cool. Then peel and slice thinly.
Mix the eggs well with salt and pepper.
Add the cream and homogenize.
For extra flavor, add a teaspoon, or less if you're not a great fan, of oregano. It will make a difference.
Wash the tomatoes well and cut into thin slices. Drain the whey from the mozzarella and slice.
Preheat the oven to 190 degrees Celsius (375 Fahrenheit).
Butter 8 small ramekins (preferably) or a large tart tin.
Roll out the dough into a rectangular sheet, half an inch thick.
Cut 8 roughly equal circles and place them in the 8 prepared shapes.
On each, put slices of potato, sprinkle with a little salt and pepper, then pour over the egg and sour cream mixture.
On top, place slices of tomato and mozzarella.
Place in the oven and bake for 30-35 minutes, until the mozzarella is nicely browned.
Leave in the tray for 5-10 minutes, then remove and place on a cooling tray. They can be served hot or cold.
Serve with a few slices of mozzarella and a sprinkle of oregano. They will be a delight, guaranteed!
Enjoy!