3 tablespoons neutral oil (safflower, vegetable, or canola)
Peel and slice the pearl onions in half horizontally. Place 12 small sprigs of fresh thyme in the bottom of a roasting pan, arrange onions atop, drizzle with oil and sprinkle with thyme leaves without the stems. Finish with salt and pepper and roast at 400 degrees for about 30 minutes, or until the onions are golden and slightly charred around the edges, reminiscent even of the roasted vegetables you might find alongside a Thanksgiving turkey. While they cool, add the dough.
To Assemble the Buns
Place a couple sprigs of the roasted thyme from the onion pan in the bottom of each skillet and arrange 7–10 roasted onion halves atop them. In a small saucepan melt the butter and dip each, covering both sides, then place one round of dough on the onions in each pan and press down firmly so it feels as though the onions have stuck to the dough and pour remaining butter over the buns. Transfer all six skillets to a baking sheet and bake in a preheated 450-degree oven for about 15 minutes or until the buns have puffed up and are lightly brown and bubbling around the edges. Flip onto a wire rack and tap the bottom of each pan to loosen the onions; if they happen to stick, scoop them out with a small spoon and place them gingerly on the buns, finish with a sprinkling of sea salt and there you have it, Onion and Thyme Butter Buns!
A Simple Alternate Version: Traditional Butter Buns Skip the onion step and instead of using the 6″ x 3.25″ cast iron pans, use only one 8″ cast iron skillet. Pour the melted butter into the bottom of this pan, roll it roughly into the shape of the skillet and make two cuts horizontally and two vertically then place the buns in the pan, flip each bun once and bake at 450 degrees for about 15 minutes or until golden and bubbly.