After you've cooked the roast (crockpot, pressure cooker or other) You can put the whole pot in the fridge (if its still too hot, careful not to crack the glass in your fridge by adding a kitchen towl underneath and over top) and the fat will float to the top and solify under the cold temperature. Take the pot out of the fridge, break of the fat parts with a butter knife and put it in a zip lock in the fridge for lard instead of cooking oil. It is a beautiful fat filled with nutrition. Or you can take the extra steps to render it in salt and water which will yield all kinds of other benefits and uses - a whole seperate subject all on its own. Call if you'd like direction on that.