Wash pork fillets, dab dry, season with salt and pepper. Heat oil in a pan and fry the pork fillets in it for about 10 minutes. In the meantime clean, wash, drain and pat dry the chanterelles.
Clean, clean and halve the mushrooms. Wash, clean and quarter the tomatoes. Peel and slice the onion. Heat 1/8 litre water, stir in the contents of the bag of "Sauce Hollandaise" with a whisk and bring to the boil.
Pull off the stove. Dice the butter and stir in little by little. Season to taste with salt, cayenne pepper and lemon juice. Take out the pork fillets and put them aside. Fry the mushrooms and onion in the frying fat.
Add the tomato, season with salt and pepper. Place the mushroom vegetables in an ovenproof casserole dish (approx. 1 1/2 litres capacity; 20x30 cm). Cut pork fillets into slices and arrange on top. Spread the hollandaise sauce on top and bake in a preheated oven (electric range: 225 °C/ gas: level 4) for approx. 10 minutes.
In the meantime, wash parsley, dab dry and chop except for a little bit for garnishing. Remove the pork fillet from the oven, sprinkle with the parsley and garnish.