Adapted from marthastewart.com
cups bread flour, plus more for work surface
teaspoon fine sea salt
teaspoon instant or active-dry yeast
cups ½-inch cubes aged Gruyere cheese
cups pitted ¼-inch-thick slices green Spanish olives
cups cool water (55 to 65 degrees), plus more as needed
In a medium bowl, stir together flour, salt, and yeast; stir in cheese and olives. Add water and, using a wooden spoon or your hand, mix until a wet, sticky dough forms, about 30 seconds, adding additional water, 1 tablespoon at a time, if needed. Cover bowl with plastic wrap and let stand at room temperature until dough has doubled in size and surface becomes dotted with bubbles, 12 to 18 hours. Generously flour work surface; scrape dough onto work surface. Lightly flour hands, a bowl scraper, or a spatula and lift edges of dough toward the center. Nudge and tuck edges of dough to make round. Place a piece of parchment paper on work surface and generously dust with flour. Gently place dough on parchment, seam-side down. If dough is tacky, lightly dust top with flour. Cover dough loosely with wax paper and two clean kitchen towels. Let down stand in a warm, draft-free spot until almost doubled in size, 1 to 2 hours. Gently poke dough with your finger; dough should hold the impression. If it springs back, let rise 15 minutes more. Ten minutes before dough has finished rising, preheat oven to 475 degrees on a conventional oven (450 degrees on a convection oven) with a rack in the lower third. Place a covered 3 1/2-quart cast-iron or enameled cast-iron Dutch oven (with plastic handle removed and screw hole plugged with aluminum foil) in center of rack. Using pot holders, carefully remove preheated Dutch oven from oven and uncover. Uncover bread and loosen bottom with a large spatula. With the aid of the parchment paper, invert bread into preheated Dutch oven so that it is seam-side up. Cover Dutch oven and transfer to oven; bake for 25 minutes. Uncover and continue baking until bread is dark brown but not burnt, 15 to 30 minutes more. Using a heatproof spatula or pot holders, gently lift bread from Dutch oven and transfer to a wire rack to cool.