Drain the sauerkraut in a colander, pressing down to remove excess liquid. Let it sit for about 5 minutes.

While the sauerkraut drains, thinly slice the red onion and any optional vegetables like bell peppers and grate the carrots. Set aside.

In a large mixing bowl, combine the drained sauerkraut, sliced onion, and chosen vegetables. Add finely chopped fresh herbs if desired.

Drizzle in olive oil and vinegar, then sprinkle with salt and pepper. Toss gently to coat everything evenly.

Cover and chill in the refrigerator for at least 30 minutes to allow flavors to meld. Ideally, let it sit overnight.

Before serving, give the salad a final toss and adjust seasoning if needed. Serve chilled.