Leek and Herb Egg Bake

Name: Leek and Herb Egg Bake
Ingredients: 2 purple scallions; 1/4 cup (1/3 oz./10 g) chopped fresh herbs, such as tarragon, chives, dill and/or basil, plus whole leaves and sprigs for garnish; 10 eggs; Kosher salt and freshly ground pepper; 1/3 cup (3 fl. oz./80 ml) heavy cream; 1/3 cup (1 1/3 oz./40 g) grated Parmesan cheese; 1/2 cup (4 oz./125 g) fresh ricotta cheese; 1/2 cup (2 oz./60 g) crumbled goat cheese; 1 Tbs. unsalted butter or extra-virgin olive oil; 2 small leeks, white and light green portions, halved lengthwise and rinsed well; Grated lemon zest for garnish; Extra-virgin olive oil for drizzling; Flaky sea salt