Butter-Lettuce Salad with Buttermilk and Herbs

In a large bowl, whisk together buttermilk, crème fraîche, and lemon juice; generously season with salt and pepper. Slowly whisk in oil. Gently toss lettuce leaves and hearts and sliced fennel with dressing, then add half each of fennel fronds, parsley, and marjoram and toss again.

Arrange salad on a platter; sprinkle with lemon zest and remaining fennel fronds and herbs. Season to taste. Serve immediately.