German-style pretzels with honey mustard sauce

The night before, spread 200 grams of baking soda in a ceramic or glass dish and bake at 300F for an hour. Handle it carefully afterwards; it is an irritant and will strip the coating from a treated stone countertop.

Combine the bread flour, kosher salt and instant yeast in a bowl, keeping the salt and yeast on opposite sides, and whisk together with a well in the middle.

Stir one and a half tablespoons of barley malt syrup into the 270 grams of water to help it incorporate.

Mix in the stand mixer on the lowest speed until smooth and supple, maybe six to nine minutes; keep a hand on the mixer as it strains.

The dough is stiff and not sticky and needs no flour on the surface. Press it: it should spring back, showing good gluten development.

Form into a ball, cover, and rise at room temperature until about doubled, about one and a half hours at 74F, closer to two in a cooler kitchen and closer to one in a hot one.

Degas the risen dough and divide it into eight portions of about 100 grams.

Form each portion into a ball, pinching the seams, and rest about five minutes -- little enough that they do not start to proof.

Turn each ball seam side up, press it flat with the fingers, roll and tuck firmly into a log, pinch the seam and roll it to about eight inches. Stop when it springs back. Cover and rest again.

Working from the pieces that have rested longest, pat each log down and fold it in half to pop the large air bubbles, pinch the seam, then roll it out to about 24 inches, pressing harder at the ends to taper them and leaving the centre thicker. Spray a little water on the surface for friction if the dough will not extend.

Lay the rope seam side down, make a U, cross the ends twice and flip them down onto the belly, pressing very hard at the connection point.

Set four per sheet tray, then go back and stretch each one out again now it has relaxed, flattening the fat part and popping any air bubbles.

Cover with oiled plastic or a proofing bag and refrigerate overnight; as little as two hours, until cold and stiff, or as long as about 18 hours.

Preheat the oven to 450F with racks in the lower and upper thirds.

Move the trays to the freezer for a few minutes while the solution is mixed -- colder and firmer pretzels hold their shape in the dip.

Add four cups of water to the baked baking soda two cups at a time, pouring slowly so it does not splash; the mixture may warm a little.

Dip the pretzels rounded side down in the solution for three to four minutes, two at a time.

Lift them into plain water for about 10 seconds to rinse off the excess, which keeps the finished pretzel from tasting bitter, then blot and return them to the baking sheet, reforming them if needed.

Deflate any big bubbles. Refrigerate the first tray while the second is dipped, and use fresh water for the second rinse.

Brush with broken-up egg white and scatter flaky salt, concentrated on the bottom curve.

Bake both trays at 450F, rotating after about 10 minutes, for about 10 to 15 minutes in all.

Cool on a rack; the thin arms go crunchy all the way through and the thick belly stays soft and bready.

For the sauce, stir together stone ground mustard, a little mayo, a little yellow mustard, honey, apple cider vinegar, salt and chili flake, by eye.