First boil the potatoes, peel them, let them cool and dice them approx. 1 cm in size.
Wash, clean and roughly chop the pak choi. Finely chop the onion, clean and quarter the mushrooms.
Sear the bacon and minced meat in a large pan in olive oil for about 3 minutes, season with salt and pepper, add the finely chopped onion and fry for another 2 minutes. Fold in the pak choi and mushrooms and fry for another 3 minutes. Mix in the potato cubes, season with herbs from Provence, deglaze with vegetable stock and fry for another 3 minutes.
Pour the mixture into a greased casserole dish and crumble the feta cheese over it. Cover the mold with aluminum foil and bake for 20 minutes at 200 ° C in the preheated oven.
Then switch to the grill, remove the aluminum foil and gratin the whole thing for about ten minutes without the cheese browning.