Slow-cooker Pot Roast

"This is one of my Mom's yummy recipes!  It makes mouth-watering, tender roast and vegetables all-in-one pot!"

1 (3 pound) beef chuck roast, we have also used a rump roast
1 pound of red-skinned potatoes, cut in half
1 large onion, quartered
1 can of cream of mushroom soup
1 packet of beef stew seasoning mix
1 Tbsp of chopped garlic
1 pound of sliced mushrooms (my Mom has also used 1 can of mushrooms)
1 (28 ounce) can of stewed tomatoes, with Italian seasonings

Combine potatoes and onion.  Put in a slow cooker that has been sprayed with non-stick cooking spray.  Place roast on top of vegetables.  Stir together soup, stew seasoning and garlic.  Pour over roast.  Top with mushrooms and tomatoes.  Cover and cook on low for 8-10 hours.