Make the Garlic Confit (if needed)Place peeled garlic cloves in a small oven-safe dish, cover with olive oil, and roast at 250°F (120°C) for 2 hours. Let cool and store in a sealed jar in the fridge for up to 1 week.
Blend the SauceIn a food processor, combine 4–5 tbsp of garlic confit cloves, feta, yogurt, mayo, vinegar, water, salt, and pepper. Blend until smooth and creamy. Add more water to thin if needed. Chill if prepping ahead.
Prepare the OnionDice red onion finely and soak in cold water for 15–20 minutes. Swirl occasionally. Drain and set aside.
Build the SaladIn a large bowl, mix chopped broccoli, cooked chicken, and drained red onion.
Toss with SauceAdd desired amount of the garlic-feta sauce and toss until everything is coated evenly. Adjust salt, pepper, or acidity to taste.
Garnish & ServeTop with extra crumbled feta, chili flakes, or herbs. Serve chilled or at room temperature.