Combine flour, salt, yeast, and water in a large bowl. Mix with hands or a wooden spoon until no dry flour remains. The bowl should be at least 4 to 6 times the volume of the dough to account for rising.

Cover bowl tightly with plastic wrap, and let rest on the countertop for at least 8 hours and up to 24 hours. Dough should rise dramatically and fill bowl.

Transfer dough to a lightly floured surface. Form into a ball by holding it with well-floured hands and tucking the dough underneath itself, rotating it until a tight ball is formed.

Pour 2 tablespoons of oil on the bottom of a 12-inch cast iron skillet or large cake pan. Transfer dough to pan, turn to coat in oil, and position seam-side-down. Using a flat palm, press the dough around the skillet, flattening it slightly and spreading oil around the entire bottom and edges of the pan. Cover tightly with plastic wrap and let the dough stand at room temperature for 2 hours.

At the end of the 2 hours, dough should mostly fill the skillet up to the edge. Use your fingertips to press it around until it fills every corner and is evenly spread, popping any large bubbles that appear.

While the dough is expanding in the skillet, preheat oven to 400°F. In a 12-inch oven-safe skillet, melt butter over medium-high heat until foaming. Add sugar and stir to dissolve. Stir in vinegar, simmer until a glaze forms, about 1 minute. Add shallots, season with salt, and stir until all the shallots are coated. Add the rosemary and thyme; transfer to oven and roast for 20 minutes. Add the cranberries to the skillet with the shallots, stir, and roast for an additional 20 minutes, 40 minutes total, until shallots are browned and tender. Let cool slightly.

Spread shallot-cranberry mixture all over the spread out focaccia in the skillet.

Drizzle with remaining tablespoon of olive oil and sprinkle with coarse salt.

Transfer skillet to oven and bake at 400 degrees for about 30-40 minutes, until golden brown. Serve warm, straight out of the oven, with a soft, creamy cheese.