Wash the potatoes and cook them in boiling water for about 20 minutes. Then rinse with cold water, peel and leave to rest. For the vinaigrette, peel and finely dice the onions. Wash the asparagus, peel the lower ends, cut off the woody ends. Cut the asparagus into very small pieces.
Heat grape seed oil. Fry the onions and asparagus until transparent. Add stock, simmer for 2 minutes. Season with vinegar, salt, pepper, sugar and pink berries. Heat oil in a pan. Fry the potatoes for about 8 minutes while turning. Season with salt and pepper. Meanwhile wash and chop the herbs and stir into the vinaigrette. Arrange roast beef and potatoes on a plate.
Heat oil in a pan. Fry the potatoes for about 8 minutes while turning. Season with salt and pepper. Meanwhile wash and chop the herbs and stir into the vinaigrette. Arrange roast beef and potatoes on a plate. Serve with the vinaigrette