I don’t remember when it was that I got it in my head that I needed to try making cassoulet, but, long story short, I finally broke my obsession with it when I got it right, which only involved one failure — which still ended up being quite tasty, even if I’d failed to allow it to have the right blackened crust due to overstirring. I’ll spare you the long story and explanation and point you to the Food Lab’s very thorough discussion on the dish, which I used as reference for ingredients and proportions.
If you don’t have salt pork, thick-cut or slab bacon is fine; try to choose a kind with a lighter smoke flavour, and instead of just browning it, cook it at medium heat to let the fat render out. If you’re lucky enough to have a large, inexpensive amount of duck confit available, swap out the chicken and duck fat and use the confit instead, but for the rest of us, duck fat and chicken pieces will do the trick.
You should err on the side of having too much stock on hand rather than too little, as this dish isn’t quite as good if it’s too dry.