Melt the butter in a non stick pan, when hot, add the onion, cook until just tender. Drain excess liquid. Set aside.
In a mixing bowl, whisk together the flour, baking powder, and salt. Stir in the celery seed.
Cut in the shortening until mixture resembles coarse crumbs.
Stir in the onion.
In a small bowl, mix together the egg and milk.
Pour the milk mixture all at once into the flour mixture.
Stir with a fork until just combined or the dough follows the fork.
Turn out onto a lightly floured surface and kneed or 30 seconds.
Roll out to ½ inch thick, cut with a biscuit cutter or a doughnut cutter.
Place biscuits on a hot casserole before it goes in a hot oven (230° C / 450° F) OR place on a baking sheet, and bake for 10-15 minutes or until golden brown and done.
Serve and enjoy.