Wash the meat and dab dry. Rub 1⁄2 tbsp. marjoram and thyme with salt, pepper, 1⁄2 each. Fry the meat in hot oil all around and place on a baking tray.
Mix the mustard and the rest of the marjoram and thyme. Spread the roast beef with it. Roast in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for 55-60 minutes (see tip).
Remove the roast and let it cool down.
Mix crème fraîche and horseradish. Wash and seed the tomatoes, dice finely and stir in. Season to taste with salt and pepper.
Wash herbs, pluck. Chop parsley. Cut chives into small rolls. Wash the flowers, possibly pluck the petals of 2 flowers. Mix herbs and petals and spread on the roast beef.
Add dip.