Step 1

Heat the oven to 350ºF. Butter and flour a metal 9 × 5-inch loaf pan and set it aside.

Step 2

In a large bowl, whisk together the flour, baking powder, salt, and baking soda. Stir in the chopped ham, scallions if using, thyme, and 1¾ cups (7 ounces) of the Gruyère (reserving the rest for topping). In a separate bowl, whisk together the melted butter, eggs, and buttermilk. Add the wet mixture to the flour mixture and stir to combine. The batter will be thick.

Step 3

Transfer the batter to the prepared loaf pan and spread it out evenly, smoothing the top. Sprinkle the remaining ¼ cup (1 ounce) cheese over the top. Bake until the top springs back when lightly pressed and a skewer inserted in the center comes out with some moist crumbs attached, 45 to 55 minutes.

Step 4

Transfer the pan to a wire rack and let it cool for 10 minutes. Then remove the bread from the pan and let it cool completely on the wire rack.