How to Make It
In a small bowl, whisk the lemon zest and juice with the olive oil, vinegar and coriander. Stir in the radishes and shallots and season with salt and pepper. Let the vinaigrette stand at room temperature for 2 hours.
Preheat the oven to 350°. Spread the brioche cubes on a baking sheet and bake for about 10 minutes, until golden and crisp. Let cool slightly, then break the cubes into coarse bread crumbs.
In a large bowl, toss all of the lettuces with the tarragon, parsley, mint and chives. Add the radish vinaigrette to the salad and toss to coat. Season with salt and pepper and toss again. Transfer the salad to plates. Top with the brioche crumbs, garnish with crushed pink peppercorns and serve.