I was trying to figure out what to do with my leftover crockpot beef brisket/eye round last night. I had about 1-1 1/2 lbs left of nice tender "pulled beef" sitting in the wonderful au jus. I looked to see what I had in my pantry and did this. Wow, it really hit the spot.
IF STARTING FROM SCRATCH, HERE'S HOW TO COOK THE CROCK POT BEEF: Place 3 lbs of beef into crock pot with beef broth, water and Italian seasoning. Cook for 10 hours on low. This beef and it's au jus can be used for a number of recipes, including chimichanga filling, tacos, shredded beef nachos, etc.
With 1-1 1/2 lbs of shredded tender beef remaining in crock pot, remove enough liquid to keep it totally drenched but not too soupy. Put that liquid aside for another use. Add chopped onion, pepper, cilantro and oregano into the crock pot with remaining beef and au jus. Turn crock pot up to high and cook for 40-60 mins.
Take mixture out of crock pot and place in bowl. Add your BBQ sauce and combine.
Place heaps of meat mixture onto the lightly toasted rye bread slices. Top with cheese. Broil until cheese melts and is bubbly brown.