Clam Chowder With Spinach and Dill

Name: Clam Chowder With Spinach and Dill
Ingredients: 48 small clams, like littleneck or Manila, well rinsed; 1 tablespoon olive oil; 1 tablespoon butter; 2 cups diced onion; 2 cups diced leek; Salt and pepper; Pinch cayenne; 1 cup diced celery; 2 bay leaves; 1 large thyme sprig; 6 ounces thick-sliced smoked bacon; 2 pounds potatoes, peeled and diced; 1/2 pound spinach, cooked briefly, squeezed dry and chopped; 8 tablespoons crème fraîche; Zest of one small lemon; 2 tablespoons chopped dill; 1/2 cup thinly sliced scallions