Trim some of the fat off the roast. Season on all sides with salt, pepper and onion powder.
Heat a small amount of oil on medium in a large pot (enough to just coat bottom of pot). Brown roast on all sides. Remove meat from pot and pour off any excess oil.
Place roast in pot and add 2 cups of water. Simmer on low heat for at least 2 hours. Meat should be well cooked, not pink. Cook longer if necessary. When done, place aside on serving dish.
In a small bowl add about 3 Tbsp of corn starch. Slowly add a small amount of water to the corn starch. Use just enough water to make a semi-thin paste. (If it's too thick it will be like cement. If it's thin like milk it won't thicken the gravy)
Slowly stir corn starch mixture in pot. Heat to almost boiling. Continue to stir and add water if needed. Add about a Tbsp of ketchup to the gravy and stir. Season with salt and pepper to taste.
Slice the roast completely and place in the pot of gravy. Heat on low until ready to serve.