Roast beef is a hands off meal because it takes little preparation and needs to cook for hours to be tender. The best way to make the roast beef as tender as possible is to cook it under steam. The easiest way to do this at home, without any special equipment, is to use parchment paper under aluminum foil to create a tight steam barrier that will allow the hot air to circulate inside the roasting pan. It's important to use a roasting pan large enough that it leaves at least 1 inch of space on all sides of the roast. This allows steam to circulate and tenderize all sides of the roast.
Preheat the oven to 350 degrees Fahrenheit. Rinse the eye of round roast under cold running water, place it in a roasting pan and pat it dry with paper towels.
Sprinkle the adobo seasoning, salt and pepper evenly over the top of the roast. The seasonings should evenly coat the top of the roast.
Cut a piece of parchment paper slightly larger than the size of the roasting pan. Make an "X" cut in the center of the paper.
Place the parchment over the top of the roast in the pan and then cover it with aluminum foil. Crimp the edges very well around the pan to not allow any steam to escape while it cooks. Cover the pan with the roasting pan lid, if it has one. Place the roast in the oven for three hours.
Remove the roast from the oven and allow it to stand for 15 minutes before removing the foil and carving.
To make a quick and easy gravy, add 2 tbsp. of cornstarch to 1 cup of cold water and slowly pour it into the hot pan drippings while stirring.
To cook vegetables with the roast, add them to the pan 30 minutes before removing it from the oven and tightly seal the foil back.