How to Make It
Preheat the oven to 325°. In a pie plate, toss the bread with 2 tablespoons of the olive oil and season with salt and pepper. Bake for about 15 minutes, until golden and crisp. Transfer the croutons to a food processor and pulse until coarse bread crumbs form.
Preheat a grill pan. In a large bowl, toss the cauliflower with 3 tablespoons of the olive oil and season with salt and pepper. Grill half of the florets in the hot pan over moderately high heat, turning, until crisp-tender and charred in spots, 7 to 10 minutes; transfer to a large bowl. Repeat with the remaining cauliflower.
Add the parsley, cornichons, lemon juice and the remaining 3 tablespoons of olive oil to the cauliflower and toss well. Season with salt and pepper. Sprinkle the bread crumbs on top and serve.