Scrub the potatoes thoroughly and cut in half crosswise. Heat oil in a pan. Peel garlic and press through a garlic press into the pan. Sauté garlic briefly and add tomato paste. Add potatoes and broth. Stir in rosemary, paprika and cumin. Cover and simmer 20-30 minutes.
Cut green tops of scallions crosswise into rings. Chop white parts of scallions and add to the potatoes. Mix cream with flour and stir with the potatoes. Simmer briefly. Season with salt and pepper. Serve ragout sprinkled with scallion greens.