Heat the 2 tbsp. oil in a heavy pan on top of the stove.
Add the rump roast to the pan and brown on all sides; seasoning with salt and pepper.
Once the pot roast is browned on all sides, place it in the crock pot.
Add the two beef bouillon cubes and the two cups of water.
Cook for six to eight hours on low or four to six hours on high.
Tip: The pot roast is done when you can stick a knife in the center easily.
For the Gravy
In a small saucepan, melt the 2 tbsp. of butter.
Add the 2 tbsp. of flour and stir; allowing the flour to cook for a few minutes.
Then add the 2 cups of reserved broth from the crock pot. If you need to, you can add water if there is not enough broth from the crock pot.
Stir and simmer until the gravy thickens to the consistency you desire.
Notes
All crock pots cook differently. You'll know when the pot roast is completely cooked when you can stick a small pairing knife in the center of the pot roast easily.