Crockpot Rump Roast Mushroom Marsala

I love using a slow cooker! The Rump Roast Mushroom Marsala is so fork tender it almost stated to shred when you cut it. I really can't find a better way to prepare any cut of meat. This came out so delicious nothing was left! I usually love to make sandwiches with the leftover, I guess next time I will buy a bigger roast!

1 (3 pound) boneless beef roast, such as bottom round or rump roast

1 1/2 tablespoons kosher salt
Freshly ground black pepper
4 cloves garlic, cut into thick slivers
1/4 cup water
1/2  cup beef broth
3/4 cup Marsala wine
1 pound of baby bella mushrooms washed, clean
oregano and garlic powder
Sprig fresh rosemary
1 teaspoon wondra flour or cornstarch
1 tablespoon butter

Place the roast in a shallow baking dish and rub with the salt and pepper garlic powder and a little oregano. Using a thin sharp knife, poke slits all over the top and sides of the roast and stuff each slit with a garlic halves. Add 1/2 cup Marsala wine. Refrigerate overnight.
 Place the beef  in the crockpot adding 1/4 cup water, 1/4 cup broth, and  marinade wine from the pan, into the bottom of the pot. Place mushrooms on top of the meat.  Put the crockpot on low for 6 to 8 hours.
Remove the roast and let sit while making the gravy.
One half hour before cook time is completed, put crockpot on high and add the remaining wine. Add a large sprig of fresh rosemary to the sauce. Stir the constarch or wondra flour into the remaining 1/4 cup broth and then whisk into the sauce. Put into the crockpot cook until thickened. Remove the rosemary sprig, stir in the butter and season with salt and pepper, to taste. Slice the beef.  Serve the sauce and mushrooms. Great over boiled rice, pasta or mashed potatoes.