San Francisco's Tartine Bakery & Cafe is known for its rustic breads, as well as the casual charm of its pastries. They also make a mean sandwich. Case in point: a bay shrimp salad served on a toasted croissant. The sweet, tiny shrimp pair perfectly with trout roe and fresh fennel. We ditched the trout roe and paired the fennel with radish and a zippy mustard-mayonnaise dressing. Use a mandoline to make quick work of shaving the fennel and radishes. You can buy cooked shrimp in the seafood department of most grocers, or poach your own peeled and deveined shrimp in barely simmering water seasoned with 1 tablespoon black peppercorns and two bay leaves. Cook the shrimp, then transfer to ice water to stop the cooking. Dry the shrimp well before using.