With salty, sweet, and creamy components, this recipe is more than just a salad: It's a fully realized side dish. Pale yellowish-white Castelfranco radicchio is usually tender and mild, but Chioggia (round) or Treviso (spear-shaped) varieties also work.
- ⅓ cup plain whole-milk Greek yogurt
- 1 Tbsp. plus 1½ tsp. sherry vinegar or apple cider vinegar
- 5 garlic cloves, 1 finely grated, 4 crushed
- 8 Tbsp. extra-virgin olive oil, divided
- 2 scallions, thinly sliced
- ½ cup panko (Japanese breadcrumbs)
- 2 medium radicchio, preferably Castelfranco, leaves separated
Mix sour cream, yogurt, vinegar, grated garlic, honey, and 5 Tbsp. oil in a small bowl; season dressing with salt.
Heat remaining 3 Tbsp. oil in a medium skillet over medium. Add crushed garlic and scallions and cook, stirring often, until golden brown around the edges, about 4 minutes. Add panko and season with salt. Cook, stirring often, until golden brown, about 3 minutes. Finely grate lemon zest directly into pan and toss a few times to incorporate. Transfer breadcrumbs to paper towels to drain; let cool. Taste and season with more salt if needed.
Place radicchio in a large bowl. Drizzle with dressing; toss gently to coat. Season with salt and scatter breadcrumbs over.
Do Ahead: Dressing and breadcrumbs can be made 2 days ahead. Cover and chill dressing. Store breadcrumbs airtight at room temperature.