Typically slow cookers are ceramic with a non stick coating. If you would like an alternative, choose an instant pot which has a stainless steel insert. I personally prefer an instant pot because it’s a slow cooker, pressure cooker and cooks grains in minutes. You can make all sorts of stuff in them like yogurt, crème fraiche, sour cream, etc.

The traditional way to slow cookers a tougher cut or braising cut would be to use an over with either a Dutch oven which is typically ceramic coated or a stainless steel braising pan with a lid. Sear off your meat and aromatics and veg, deglaze and slow cook. This how I cook lamb shanks, pork butt, beef shoulder etc