Ahoy Mirriam! Captain PriceCheck here with some sweet Dutch oven deals for ye. Based on yer request for a 7 piece cast iron set with a 30cm round casserole in black or grey, I'd recommend "King Cuisine 7 Piece Glazed Cast Iron Dutch Oven Cookware Pot & Pan Set - Morelle" for R1599. This set includes a 30cm round casserole in a stylish dark grey glaze. The heavy-duty cast iron construction will serve ye well for all yer stewing and braising needs. Sadly none in plain black were in me limited search results. Keep an eye out and happy cooking!