Cut fennel bulbs in half lengthwise, remove the tough core, and slice crosswise into ⅛-inch pieces using a mandoline or sharp knife. Place sliced fennel in a large mixing bowl.
2 medium fennel bulbs
Using a paring knife, cut away the peel and all white pith from the oranges. Cut between membranes to release clean orange segments. Add the segments to the bowl with the fennel and squeeze any juice from membranes over top.
3 navel oranges
Toss in thinly sliced red onion (if using, rinsed), torn fresh mint leaves, and sliced black olives (if using). Drizzle with extra virgin olive oil and wine vinegar. Season with salt and black pepper to taste.
1 small red onion, 0.25 cup fresh mint leaves, 0.25 cup black olives, 3 tbsp extra virgin olive oil, 1 tbsp red or white wine vinegar, salt, black pepper
Toss everything until evenly coated. Cover and refrigerate for 30 to 60 minutes to allow fennel to soften while remaining crisp. Stir once halfway through marination to redistribute dressing.
Before serving, drain any excess liquid pooled at the bottom of the bowl. Taste and adjust salt or vinegar if needed. Garnish with fresh fennel fronds and serve immediately chilled.
fennel fronds
