Brown meat in oil in the pressure cooker. Add the salt, pepper, onion, broth, and 1/2 cup water. Cover and bring to full pressure. When steam appears, reduce heat to low and cook for 25 minutes. Reduce pressure completely and add the carrots and potatoes. Cover and simmer (not under pressure) for 20 minutes, until tender. Remove meat and vegetables with a slotted spoon and skim off excess fat.
Combine flour and 2 tablespoons cold water until smooth; stir into the simmering broth. Continue simmering, stirring, until broth is thickened.
Serves 6 to 8.