InstructionsStep 1: Slice the roast into large bite-sized pieces and trim the excess fat.Step 2: Place the meat in a large metal roaster and sprinkle with half tsp pepper. Sear over medium-high heat in a little oil for about 10 minutes until all sides are slightly browned.Step 3: Add the broth to the skillet once the beef is lightly browned along with the onion, soup mix, A-1, garlic, horseradish, mustard, half teaspoon kosher salt, and 1 1/2 teaspoon pepper. Then, dot with butter. Bring everything to a boil. Put the lid on and adjust the heat to low and simmer for about 1 1/2 hours, stirring about 2 to 3 times as it cooks.Step 4: Now, add the mushrooms and simmer for an additional 15 to 20 minutes, covered.Step 5: Whisk the cornstarch with cold water until well mixed, then add this to the skillet. Stir and simmer for a couple of minutes more until the sauce has slightly thickened. Cover when done and set aside.Step 6: Following the package directions, cook the noodles in a large pot of salted boiling water until al dente. Drain when done and add to the pot of beef. Toss well and serve immediately with some crust bread and butter or a side of veggies like green beans, or a nice garden salad. Enjoy!