cabbage and lime salad with roasted peanuts

INGREDIENTS

• 1/2 small red cabbage, trimmed, cored, and shredded (about 6 cups)
• 1/2 small green cabbage, trimmed, cored, and shredded (about 6 cups)
• 1 tablespoon kosher salt, plus more to taste
• 1 bunch fresh baby spinach, stemmed and cut into 1/2-inch wide ribbons (about 4 cups loosely packed)
• 1/4 cup fresh lime juice (from about 2 small limes)
• 1 tablespoon Dijon or other salty prepared mustard
• 1/2 teaspoon ground cumin
• 1/4 cup peanut oil
• 1/2 cup roasted unsalted peanuts, coarsely chopped
• Freshly ground black pepper