Peel, seed, and chop tomatoes. Slice summer squash and zucchini. Dice potatoes. Place lamb and vegetables in crockpot. Mix salt, garlic, thyme, and bay leaf into stock; pour over lamb and vegetables. Cover and cook on low 8 hours. (Don't peek. Lifting the lid prolongs cooking time. ) Turn to high. Blend flour and butter, then shape into small balls. Drop into stew and cook, stirring several times, until thickened. <br> Serve over hot noodles or rice.