1/2 pound green cabbage (about 1/2 medium head), shredded fine
1/2 pound red cabbage (about 1/2 medium head), shredded fine
2 large carrots, peeled and grated
juice from 1 lemon
2 teaspoons kosher salt, or 1 teaspoon table salt
1/2 small red onion, minced
1/2 cup mayonnaise
1 tablespoon rice vinegar
Ground black pepper
Toss cabbage and carrots with salt and lemon juice in colander set over medium bowl. Let stand until cabbage wilts, at least 1 hour and up to 4 hours.
Place wilted cabbage and carrots into the bowl. Rinse thoroughly in cold water (ice water if serving slaw immediately). Pour vegetables back into colander, pressing, but not squeezing on them to drain. Pat dry with paper towels.
Pour cabbage and carrots back again into bowl. Add onions, mayonnaise, and vinegar; toss to coat. Season with pepper to taste. Cover and refrigerate until ready to serve.