Stir together your mustard, oil, vinegar, salt and pepper in your 2-3 quart crock pot (I used Dotty, my 2.5-quart polka dot crock pot)
Add your potatoes and onion and stir
Cover and cook on low for 6-8 hours or high for 3-4 hours
Notes
As with any of our recipes, calorie counts and nutritional information varies greatly depending on which products you choose to use when cooking this dish.
All slow cookers cook differently, so cooking times are always a basic guideline and should always be tested first in your own slow cooker and time adjusted as needed.