Peel the celery and cut into approx. 1 cm thick slices. Heat the fat in a coated pan (the pan should have a lid) and put on medium heat (!). I especially like it when a mixture of butter and vegetable oil is used, but you should decide that for yourself. Put in the celery slices and fry them slowly without a lid. When turning, add salt and pepper to the fried sides (it will stick better). The whole roasting process takes about 15 minutes for me. Then the slices are nicely cooked through, slightly browned and crispy. Then place the sliced feta on the celery, put the lid on the pan and cook for another 3 minutes.
The dish tastes very good with mashed potatoes or fried potatoes and salad. I also like it cold, e.g., on a slice of white bread.