Every Monday morning of my childhood, the fridge was a treasure trove. My nan would take the leftover topside or silverside from Sunday’s roast, slice it thin, and slather it with enough horseradish to make your eyes water. This roast beef and horseradish wrap was a tradition as sacred as the roast itself, and it remains a highlight in my collection of Best Wraps.

British food often gets a bad rap for being bland, but anyone who says that has clearly never had a proper hit of English horseradish. This wrap is my nod to those nostalgic Monday leftovers, but given what I call a “gastropub glow-up.” If you’re looking for British pub lunch ideas, we aren’t just slapping meat in bread here; we’re creating a gourmet beef wrap, complete with sweet, sticky onions and peppery greens. This is a quintessential Sunday roast leftovers recipe that turns yesterday’s dinner into today’s gourmet treat.

The Secret to a Proper Roast Beef Wrap

The absolute most important thing here—and I cannot stress this enough—is how you handle the beef. If you’re using leftovers, they’ve likely been in the fridge. You might be tempted to zap them in the microwave, but please, for the love of a good Sunday dinner, don’t do it!

Microwaving turns beautiful, medium-rare beef into something resembling a grey pencil eraser. If you enjoy traditional British fare like my Proper Slow Cooker Beef and Guinness Stew, you know that texture is everything. Instead, let the beef sit on the counter for a bit to take the chill off, or give it a very quick “flash-warm” in a pan that’s barely warm. You just want the fats to soften so the flavor sings.

Why ‘Ale-House’ Onions?

In the gastropubs where I trained, we never just used raw onions. They’re too sharp and can overpower the delicate beef. Instead, we cook them down with balsamic vinegar and a touch of sugar. This mimics the rich, savory-sweet depth of a proper onion gravy. It’s dead simple to do but makes the wrap feel like a meal you’d pay twenty quid for in Central London.

The Layering Strategy

Nothing ruins a lunch faster than a soggy wrap. To avoid this, I use a little trick: the “Rocket Barrier.” By spreading your horseradish cream first and then immediately covering it with a thick layer of rocket (that’s arugula to my American friends), you create a protective shield. Unlike my 20-Minute Creamy Chicken Caesar Wraps, this one uses rocket to keep the texture crisp. The greens keep the moisture of the sauce away from the tortilla, ensuring every bite stays sturdy.

As with many Samuel Thompson recipes, the focus is on quality ingredients. Serve this with a handful of proper thick-cut crisps (kettle chips) and maybe a cold pint of bitter if it’s the weekend. It’s comfort in a wrap, plain and simple. Tuck in, you’ve earned it!