Peel and chop the carrots and chop into 1 cm cubes. Wash the mushrooms and slice.
If you are using white asparagus then peel it and chop off the wooden bits. If you are using green asparagus then just chop off the wooden bits.
Blanche the asparagus for approximately 2 minutes in hot water with a pinch of salt and a pinch of sugar.
Weigh the peas and prepare the chicken stock.
Now let us prepare the roux. Melt the butter in a saucepan and add the flour into the melted butter. Whisk until the flour turns golden and yellow.
Carefully add little portions of the stock/broth to the flour-butter mixture. Keep on stirring to even up the lumps.
Now add in the cream, mushrooms, vegetables, asparagus and peas. Leave to simmer on medium heat for approximately 8 minutes, until the vegetables are cooked.
Now carfully add in the egg yolk (if using) and quickly stirr into the sauce. Thickening the sauce with egg yolk, gives it a rounded and taste provides it with a special sheen.
Season the Hühnerfrikassee with salt and pepper. Add some lemon juice to taste.
Add in the chicken, and leave to warm up in the sauce for approximatley 5 minutes. The sauce no longer needs to cook.
Serve with white rice or mashed potatoes.