This savory, satisfying loaf is adapted from Joy of Cooking.
Preheat the oven to 350° F with a rack in the center. Grease a 9 x 5-inch (8-cup) loaf pan. In a large bowl, whisk together the flour, baking powder, baking soda, salt and pepper. Add the zucchini, cheeses, shallot and herbs and toss to separate and coat with flour.
In a small bowl or glass measuring cup, whisk together the eggs, buttermilk and melted butter. Pour into the bowl with the flour mixture and mix until just combined. Bake for about 55-60 minutes, until a toothpick or cake tester inserted in the center comes out clean. Let cool in the pan on a rack for 5 to 10 minutes before unmolding to cool completely on the rack.