Dry mushroom soup mix can be used in place of the leek soup mix. To enhance the flavor of mushroom soup, add 1 small sliced leek or onion along with the celery.
In this recipe, the biscuits are cut into small pieces to speed their cooking. Because biscuits cook best in an almost-boiling sauce, quickly add them and replace the slow cooker's lid so the sauce stays piping hot.
For a family supper, serve the chicken and dumplings with sweet corn kernels, a crisp, mixed-green salad and brownie sundaes.