With only six ingredients, you can create a fork-tender pot roast and a side of au jus packed with flavor.
Press pepper evenly onto all surfaces of beef Cross Rib Roast. Heat oil in stockpot over medium heat until hot. Place pot roast in stockpot; brown evenly. Pour off drippings.
Add broth and 2 cups of leeks to stockpot; bring to boil. Reduce heat; cover tightly and simmer 2 to 3 hours or until roast is fork-tender.
Remove roast; keep warm. Skim fat from cooking liquid. Bring liquid to a boil and reduce for 5 minutes. Combine cooking liquid and remaining 1 cup leeks in stockpot. Reduce and simmer, uncovered, 6 to 8 minutes or until leeks are tender. Stir in mustard; remove from heat. Carve roast into slices. Serve with au jus.