Preheat oven to 325°F (163°C).

Brown rump roast in shortening in a Dutch oven over medium-high heat.

Arrange peeled potatoes, celery pieces, and quartered carrots around the browned meat in the Dutch oven.

Sprinkle salt and pepper evenly over the meat and vegetables.

Top the meat with dried apricots and sliced mushrooms.

Pour catsup evenly over the meat and vegetables.

Cover the Dutch oven tightly.

Bake in the preheated oven for 2 1/2 hours, or until the meat and vegetables are tender.

Baste the meat and vegetables occasionally with the pan juices during baking.

If needed, add a little water to the Dutch oven to prevent burning during baking.

Serve hot, spooning the pan juices over the meat and vegetables.