Place daikon and carrots in a large bowl and toss with salt. Let stand for 20–30 minutes, until vegetables begin to release their moisture.

Pack a handful of julienned vegetables into the jar, then add some of the jalapeño and garlic. Adjust heat by adding more or fewer jalapeños or by removing seeds and membranes. Continue layering until all vegetables are packed tightly into the jar. If using, drizzle fish sauce over the vegetables. Press down firmly to encourage the vegetables to release enough liquid to create a natural brine.

If vegetables are not completely submerged after pressing, top off the jar with a 2 percent salt brine. To make a

2 percent salt brine, dissolve 1 tablespoon kosher salt in 2 cups of non-chlorinated water before adding it to the jar.

Add a fermentation weight to keep the vegetables submerged and cover with an air lock lid. Ferment at room temperature (about 64–75°F), out of direct sunlight, for 7–10 days, depending on the ambient temperature.

Begin tasting after 5 days. When the pickles have reached the desired tang and acidity, remove the weight, seal the jar, and refrigerate. The pickles will continue to develop slowly in the refrigerator and are best enjoyed within about 6 months.