Bagels with Ham Salad

Start with the pickle, because it needs the most lead time and the least attention once it's made. Red onion sliced thin — thin meaning you can see light through it, not rings you could stack a burger patty with — goes into a scalded jar. Scalding isn't tradition for tradition's sake: it kills whatever's lingering on the glass so your pickle doesn't turn cloudy or off in a few days. The vinegar-water-sugar brine, boiled just until the sugar dissolves (watch for the liquid turning clear, not cloudy — that's your cue, not a stopwatch), does two things at once: the heat softens the onion's bite without cooking it limp, and the sugar balances the vinegar's sharpness so you get sweet-sour, not just sour. Apple cider vinegar here isn't precious — any vinegar with a fruit note works; white wine vinegar is fine, malt vinegar will fight the mustard later, so skip that one. Pour it boiling over the onion — the heat is what does the quick-pickling; cold vinegar on raw onion just gives you onion in puddle, not pickle. Seal and chill: a few hours gets you bendy, bright pink-edged onion; overnight gets you something closer to a proper pickle. This keeps in the fridge well past the sandwich — use it on cheese, in salads, wherever you want brightness without raw onion's rawness.

The ham: farmhouse, cooked, meaning something with actual grain and bite — leftover gammon from the Sunday roast is exactly the right instinct, or a thick-cut ham from the deli counter, not the thin pre-sliced stuff from a packet, which turns mushy once dressed and gives you no texture against the cream. Cut small or grate it — grating is faster and gives a better dressing-to-ham ratio if your knife skills aren't surgical.

Mayonnaise and crème fraîche are doing different jobs, which is why neither substitutes cleanly for the other. Mayonnaise brings emulsified fat and a neutral creaminess that coats; crème fraîche brings cultured tang and a lighter body. If you've only got soured cream, use it — it's close enough in acidity, just slightly thinner, so go a little lighter on mustard to compensate. Greek yoghurt works in a pinch but it's sharper and leaner; add a touch more mayonnaise if you go that route.

The two mustards — Dijon for heat and backbone, sweet (something like a honey or wholegrain sweet mustard) for the fruit-note sweetness — aren't interchangeable with "just use mustard." Dijon alone is sharp without roundness; sweet alone is flat without bite. Together they do what the sugar did in the pickle: balance one edge against another. If you've only got English mustard, use a third of the amount — it's far hotter and will dominate everything else.

Rocket and watercress aren't decoration, they're the one place in this sandwich that's raw, peppery, and alive — rocket's mustard-oil bitterness and watercress's sharp bite both play the same game as the Dijon, just with chlorophyll instead of a jar. If you can't get watercress, baby spinach with a squeeze of lemon gets you some of the way, though you lose the pepper.

And the bagel — warm it, don't toast it to crisp. Warming softens it enough to bite through without the filling squeezing out the sides, and brings back the yeasty smell that a cold bagel from the fridge loses. A domestic toaster set low, or a few minutes cut-side-up under the broiler watching it, not timing it — you want it soft and warm through, not browned and brittle.

This feeds eight as a light lunch — more if you're serving it alongside something, fewer if it's the whole meal and people are hungry. The patience here isn't in the cooking, which is quick; it's in the waiting for the pickle, and in resisting the urge to eat the sandwich the moment you've built it — give the bagel a minute to warm through properly, and the whole thing holds together instead of falling apart in your hands.