Wash the roast and pat dry. Season with salt and pepper. Wash the parsley and pluck the leaves from the stalks. Cover the roast in scales with bacon and parsley and put it on a fat pan.
Cook in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 50 minutes. After 30 minutes, deglaze with 1/4 litre water. In the meantime, puree tuna, capers and anchovy fillets for the sauce and mix with crème fraîche.
Add 100 ml of gravy. Season to taste with salt, pepper and lemon juice. Clean and wash spring onions and cut into bite-sized pieces. Fry in hot oil while turning for about 5 minutes and season with salt and pepper.
Deglaze with 100 ml water, bring to the boil and remove the spring onions. Add the prepared sauce to the liquid, warm up lukewarm. Cut the roast open and arrange on a plate with the vegetables and some sauce.
The rest of the sauce extra is fine. Serve garnished with lemon and caper apples.