Let the spinach thaw slowly in the pan.

Cut the onion into small cubes, fry in the clarified butter with the ham cubes.

Peel the potatoes and cut into slices, then cook them in salted water until they are firm to the bite.

Season the onion and diced ham mixture generously with salt and pepper. Also add pepper and salt to the thawed spinach.

Put the hollandaise sauce in a mug and whisk with the dash of milk and parsley.

Put the mixture of onion and ham in a casserole dish, add the drained potato slices and the spinach. Mix everything together and finally top it with the Hollandaise. Cover everything with the grated Gouda cheese.

Bake in the oven at 180 degrees for about 30 minutes. Finally, turn on the grill for a few minutes so that the cheese turns brown.

Bon appetit!