How to Make Roast Beef Sandwich
- Take a bowl, mix onion and a tablespoon of salt.
- Rinse the onions with cold running water after 20 minutes.
- Drain and squeeze the onions and make sure the excess water has been removed.
- Marinate the onions in vinegar for at least 30 minutes or up to 24 hours.
- For making the sauce take a small bowl, mix the mayonnaise, sour cream, horseradish, zest and 2 teaspoons salt.
- Season the mixture with black pepper and hot sauce as per your taste. Refrigerate the horseradish sauce for at least 30 minutes.
- Preheat the broiler.
- Slice the rolls in half lengthwise.
- Using your hands, shallowly scoop out the inside of each half.
- Transfer the rolls to a baking sheet and arrange scooped-side up.
- Now slightly toast the buns for about a minute.
- Spread the horseradish sauce inside the buns.
- On each of the roll bottoms, put 2 tomato slices.
- Now place the roasted beef on top of the tomatoes.
- Lay down a layer of American cheese on the sandwich.
- Top the sandwich with some of the onions and watercress and cover with the tops of the roll and broil until the cheese gets melted.
The roasted beef sandwich has been one of the most relished fast food snacks in America since the late 19th century.