Low and slow is my advice too - but also IME there's something magical that happens when you use creamy soups as a starter with your meats. I spent years trying to make something healthier than my mom's roast beef recipe, which is basically cream of mushroom soup and onion soup mix plus a roast, but nothing I did could make it fall apart and stay moist like hers. I settled on using real onions in place of the onion soup mix which helps lower the salt content a bit but my family often asks me to just make it like my mom did.