- Heat oil and butter in a skillet and sauté onions over medium-low heat until well browned.
- Add garlic and flour and continue to cook while stirring for an additional 5 minutes.
- Add stock and water and bring to a simmer, stirring to deglaze the bottom of the skillet.
- Pour the onion mixture into the bottom of a slow cooker.
- Place the roast on top and add black pepper.
- Cook on low for 6.5 hours. When finished, the slow cooker should then switch to warm.
- When ready to serve, remove roast and set aside loosely covered with foil.
- Puree the onion gravy in a blender or food processor.
- Remove the netting from roast, slice and serve with gravy.
*For a gluten free version omit the flour. Once the gravy is blended place it in a saucepan and bring it to a simmer. Add one teaspoon of cornstarch mixed with 2 tablespoons of cold water and then return gravy to a simmer.