Put the couscous in a bowl. Wash the asparagus, cut off the woody ends. Cut the stalks diagonally into pieces. Bring to the boil with 300 ml water, the frozen peas and 1 tbsp. olive oil. Pour over the couscous and let it swell covered for about 5 minutes.
In the meantime wash, clean and chop the radishes. Wash the salad and spin dry. For the dressing, mix lemon juice and 2-3 tbsp. oil, season with 1 tbsp. sugar, salt and pepper.
Loosen the couscous, mix with the dressing. Fold in radishes and salad. Season to taste with salt, pepper and lemon juice. Pour the couscous salad into a bowl and arrange the roast beef on top. Season with pepper. Serve with herb quark.