Gat Kimchi (Mustard-Green Kimchi)

Toss mustard greens with salt in a large bowl. Let stand, tossing once or twice, for 30 minutes.

Meanwhile, combine water, pear, daikon, ginger, garlic, scallion and lemon juice in a blender; process until smooth. Strain the puree through a fine-mesh sieve set over a bowl, pressing on the solids to extract the liquid. Discard the solids. Stir lemon zest into the liquid.

Pack the mustard greens and any accumulated liquid into a sterilized quart jar. Pour the lemony liquid over the greens. Press down on the greens with a wooden spoon or spatula until they are submerged.

Screw on the lid. Place the jar in a cool, dark spot and ferment at room temperature for 5 to 7 days. (If it's hot, 2 to 3 days may be enough). When it's fermented to your liking, refrigerate for up to 3 weeks.