Place butter in a 9” x 5” loaf pan. Transfer to microwave and cook on high until butter is melted, about 20 seconds. Swirl to grease loaf pan and pour remaining butter into a medium bowl.
Add eggs, almond flour, baking powder, and 1/2 teaspoon salt. Stir until smooth, then add herbs and gruyere. Season generously with black pepper. Fold to combine and transfer mixture to greased loaf pan.
Microwave until bread is puffed and cooked through, approximately 4 minutes. Let cool slightly before running a knife around the pan and transferring to a cutting board. Slice and serve.