Clean or peel, wash and chop the soup greens. Peel onion and cut into fine slices. Drain the peppers and cut the pods horizontally. Place the roulades on the work surface and brush each with 1 tsp. mustard.
Place 1 pepper half and some onion slices on each end of a roulade. Roll up the roulade from the coated side and pin it with a wooden skewer. Heat the oil in a roasting pan and fry the roulades in it while turning.
Season with salt and pepper and remove from the roaster. Put the soup greens and the remaining onion slices into the hot frying fat, fry in it and stir in the tomato paste. Season with salt, pepper and thyme and pour on 1/2 litre of hot water.
Stir in the stock. Add roulades and bring to the boil. Cover and braise over low to medium heat for about 1 1/2 hours. Clean and wash the Brussels sprouts and cook in little boiling salted water for about 20 minutes.
Remove the roulades from the stew stock, arrange in a deep dish and keep warm. Puree the vegetables in the casserole with a chopping stick. Add some water if necessary. Season the sauce to taste with salt and pepper, heat up again and pour over the roulades.
Garnish with thyme. Drain the Brussels sprouts, season with nutmeg and add. Boiled potatoes taste good with it.