Wash the potatoes and cook in plenty of boiling salted water for about 15 minutes. Rinse with cold water and remove the skin. Clean and wash the sugar peas. Peel and chop onion.
Wash the saddle of lamb, dab dry and rub with salt and pepper. Roast in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for 40-45 minutes. In the meantime, peel the garlic and press it through a garlic press.
Wash the rosemary, thyme and a stalk of parsley. Pluck rosemary needles. Set aside some rosemary, thyme and some parsley for garnishing. Chop the remaining herbs. Crumble the toast.
Mix with chopped herbs, egg yolk and crème fraîche. Season with a little salt and pepper. Heat 30 g fat in a pot and sauté the flour in it. Deglaze with broth and milk while stirring. Add lemon zest and simmer for about 5 minutes.
Season to taste with salt, pepper and lemon juice. About 10 minutes before the end of the frying time, spread the herb mixture on the roast and finish frying. Put deep-frozen peas in approx. 1/8 litre boiling salted water and stew covered for 8-10 minutes.
Add sugar peas after about 4 minutes and cook. Heat clarified butter in a pan and fry the potatoes until golden brown all around. Season with salt and lemon pepper. Drain the vegetables, heat the rest of the fat, fry the onion in it until transparent and toss the pea vegetables in it.
Take the saddle of lamb out of the oven, cover and let it rest for about 5 minutes. Remove the meat from the bone, cut into slices and place back on the bone. Garnish with remaining herbs and arrange on a preheated plate together with vegetables and roast potatoes.
Serve the sauce extra and sprinkle with lemon peel strips and lemon pepper to taste.