Melt butter in a large skillet and add scallions, garlic, and herbs. Cook over medium heat for about a minute. Gradually add spinach, allowing each handful to wilt before adding more. Season with salt and pepper.
Beat eggs and egg yolks with half the cheese until fairly smooth, then add milk and cream, a bit of nutmeg, 1/2 teaspoon salt and a grinding of pepper.
Preheat oven to 375 degrees. Place spinach in the bottom of pie crust and crumble remaining cheese on top. Add custard. Bake until set and lightly browned, about 35-45 minutes. Let rest 5 minutes before serving.
recipe notes
(Adapted from The Greens Cook Book by Deborah Madison)