Cut venison into medallion size chunks. Place into canning jars. Your choice of quart or pint. Add cut onion. Cut onion into 1/4" to 1/2" slices. Add whatever amount you like into the jars.
Wipe rims of jars and put on lids and rings. Place into pressure cooker. Fill with water up to neck of jars. Put top on the pressure cooker with a 15 weight. If you have hard water, you can add a splash of white vinegar to stop the white film it can put on jars.
From the time the weight starts to "jingle" cook for 45 minutes for pints and 50 minutes for quarts.
Make sure pressure is relieved from canner before removing lid. Let cool and put it in your pantry.
You can mix this with bar-b-q sauce and put on sandwiches or mix with cream of whatever soup you like and put over noodles. Drain off the liquid first or drain and save to make gravy.