Beef Rib Eye Roast with Red Wine Mushroom Sauce

1 small onion, very thinly sliced 3 1/2 pounds boneless beef chuck roast 1 teaspoon kosher salt 1 teaspoon freshly ground black pepper 4 large cloves garlic,[...]

3 pounds beef roast, rib-eye boneless * 3/4 teaspoon salt divided 1/2 teaspoon black pepper divided 1/2 cup onion chopped 1/2 cup red wine dry * 1 tablespoon[...]

1 (3 -4 lb) chuck roast (okay to use from frozen state) 1 small onion , very thinly sliced 4 large garlic cloves , very thinly sliced 3 cups full-bodied red[...]