Roast Beef Sandwich with Horseradish Mayo
Introduction
A great roast beef sandwich is built on thin slices of a properly rested and chilled roast, a sharp condiment like horseradish mayo, something crunchy and sturdy bread that holds it all together.
This version layers rosy, home-roasted grass-fed rostbiff with punchy horseradish mayo, quick-pickled red onion and peppery rocket on sourdough or rye. Home-roasted beef has a depth of flavour and a tenderness that deli slices rarely match, and a leftover Sunday roast works just as well.
Below you will find how to roast and slice the beef for sandwiches, the horseradish mayo and how long leftovers keep.
Ingredients
For 4 servings
- 1kggrass fed rostbiff (rump centre)or 400g leftover roast beef
- 1 tbspolive oil
- sea salt and freshly ground black pepperto season
- 1/2 cup (125g)whole-egg mayonnaisehorseradish mayo
- 2 tbspprepared horseradishor 1 tbsp freshly grated (horseradish mayo)
- 1 tspDijon mustardhorseradish mayo
- 1 tsplemon juicehorseradish mayo
- 1 smallred onionthinly sliced (pickled onion)
- 60mlred wine vinegarpickled onion
- 1 tspcaster sugarpickled onion
- 1/2 tspsaltpickled onion
- 8 slicessourdough or rye bread
- 20gbuttersoftened
- 2 cups (40g)rocket
- 4 slicesaged cheddaroptional
Utensils
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- Ovenproof frying pan
- Digital probe thermometer
- Carving board
- Long, sharp slicing knife
- Aluminium foil and cling film
- Small mixing bowls
- Measuring spoons
- Bread knife
Cooking Steps
Season and sear
Take the rostbiff out of the fridge 20 minutes before cooking and heat the oven to 180C (160C fan). Pat it dry, rub with the oil and season generously. Sear in a hot ovenproof frying pan for 6 to 8 minutes, turning, until browned all over.
Roast to temperature
Transfer the pan to the oven and roast for 25 to 35 minutes, until a probe in the centre reads 56 to 58C for medium rare. Pink beef gives the most tender, juicy sandwich slices.
Rest, then chill
Rest the beef on a board, loosely covered with foil, for 15 minutes. Once it has stopped steaming, wrap it and refrigerate for at least 3 hours or overnight, so it firms up for thin slicing.
Pickle the onion
Stir the vinegar, sugar and salt together until dissolved, add the onion and leave for 20 minutes, then drain.
Mix the horseradish mayo
Combine the mayonnaise, horseradish, mustard and lemon juice, season to taste and chill until needed.
Slice thinly across the grain
Using a long, sharp knife, slice the cold beef across the grain as thinly as you can, about 2 to 3mm. Allow about 100g per sandwich.
Build the sandwiches
Lightly toast the bread if you like, then butter it right to the edges. Spread horseradish mayo on both slices, add the cheddar if using, then pile on the beef in loose folds. Top with pickled onion and rocket, season with pepper, close and cut in half.
Nutrition
Per Serving
Recipe serves 4Nutritional values are estimates only and may vary based on specific ingredients, brands, cuts, cooking method, and portion sizes. For medical or dietary purposes, please consult a qualified nutritionist.
Tips and Pairing
People Also Ask
What goes on a classic roast beef sandwich? +
A classic roast beef sandwich has thinly sliced roast beef, a sharp condiment such as horseradish or mustard, and something fresh like rocket, lettuce or tomato, all on sturdy bread such as sourdough or rye. Pickled onion adds crunch and tang, and a slice of aged cheddar or Swiss cheese makes it richer. Keep the fillings simple so the beef stays the star.
What is a good condiment for a roast beef sandwich? +
Horseradish is the classic condiment for a roast beef sandwich, because its clean heat cuts through the richness of the beef. Mixed into mayonnaise it becomes creamy and mild, while horseradish cream made with sour cream tastes sharper. Dijon or wholegrain mustard, garlic aioli and a tangy tomato chutney are also excellent choices.
What makes a really good roast beef sandwich? +
A really good roast beef sandwich starts with a well-rested, fully chilled roast sliced paper thin across the grain, so every bite is tender. Add a punchy condiment, something crunchy or pickled for contrast and bread sturdy enough to hold the fillings. Butter the bread right to the edges so it stays crisp rather than soggy.
What cut of beef is best for roast beef sandwiches? +
Lean, evenly shaped roasting cuts make the best roast beef sandwiches, and rostbiff, the trimmed centre of the rump, is ideal. It slices into neat, tender pieces with no gristle when roasted to medium rare, chilled and cut thinly across the grain. Rump, eye fillet and leftover scotch fillet also make excellent sandwiches.
How long does leftover roast beef last in the fridge? +
Leftover roast beef should be used or frozen within two to three days, in line with Food Safety Information Council advice on leftovers. Refrigerate it once it stops steaming, ideally within two hours of cooking, and keep it covered in a sealed container. Slice only what you need, and reheat any hot dishes until steaming.
