Heat 2 tablespoons butter and the rosemary in a small skillet over medium heat. Cook the butter until it begins to brown and the rosemary is crisp, about 3-4 minutes. Remove the rosemary from the skillet, let cool, then finely chop the fried leaves. Position a rack in the lower third of the oven. Preheat the oven to 450°. Place a 6 cup standard popover pan in the oven. Alternately, you can use a 12-cup muffin pan and make 10 mini popovers. In a medium bowl, vigorously whisk together the milk and eggs until frothy, about 1 minute. Add the browned butter, 1-2 tablespoons chopped rosemary, the flour, salt, and pepper - if using, and whisk to combine. It's OK if there are small lumps. Carefully remove the popover pan from the oven and add 1 teaspoon of butter to each cup of the pan. Swirl the butter around the cups to grease the pan. Evenly divide the batter between the popover cups, filling them about 3/4 of the way full. Transfer to the oven and bake for 20 minutes. Lower the oven temperature to 350°. Bake another 15-20 minutes, until puffed, golden and crisp. Meanwhile, make the honey butter. Combine 6 tablespoons butter and the honey. Mix 1 tablespoon of the chopped rosemary with the flaky sea salt. Serve the warm popovers immediately, with honey butter and a sprinkle of rosemary salt.