For the best crunch, keep the dressing separate if making this salad ahead and toss it with the vegetables just before serving. If raw red onion tastes too sharp, soak the slices in cold water for 5 to 10 minutes, then pat dry before adding to the salad. You can add extra protein such as grilled chicken, canned tuna, or boiled eggs on top to turn this into a complete keto meal without significantly changing the macros. Store undressed salad in an airtight container in the refrigerator for up to 3 days and dressed salad for up to 24 hours.