Peel the sweet potatoes and cut into cubes. Mix with olive oil, sea salt and pepper in a bowl. Put in a baking dish and bake in the oven for 20 minutes.
During this time, dice the feta, wash and quarter the tomatoes, take the baking dish out of the oven for a moment, sprinkle the sweet potatoes with feta and tomatoes and bake for another 10 minutes.
Sprinkle the finished casserole with herbs from Provence and / or dried tomato flakes, if you like.