In a large bowl, combine the flour, salt, and yeast, then stir to combine. Use a wooden spoon to create a well in the center of the flour mixture, then slowly pour in the warm water and mix until a sticky, shaggy dough forms. Cover the bowl with a dish towel, set it in a warm place, and allow it to rest until doubled in size, about 6 hours. Once ready, the dough should be puffed up and bubbly.
While the dough rests, roast the garlic. Preheat the oven to 400 degrees, rub off the excess layers of papery skin from each garlic head, and slice off the tops to expose the cloves. Place each head on a small square of aluminum foil, then divide and drizzle 1 tablespoon of olive oil over the top of the garlic. Wrap the heads tightly in the foil and bake until fragrant and tender, about 45 minutes. Remove from the oven and allow to completely cool.
Once cool, carefully remove each garlic clove from their individual pockets. Place in a small ramekin and set aside.
Flour a clean surface, turn out the dough, and punch down. Push each clove of garlic into the bread, making sure to space them out. Fold over the dough until the garlic has fully incorporated and the dough is smooth, about 4-6 times. Sprinkle on extra flour as needed. Place the dough back in the bowl, cover with the dish cloth, and allow to rise again for 1 hour, or until doubled in size again.
Place a large Dutch oven or a large stainless-steel pot in the oven (with the racks arranged in the middle), then preheat to 450 degrees. Once preheated, remove the pot from the oven, and carefully transfer the dough. Quickly drizzle the remaining 2 tablespoons of olive oil over the top, sprinkle on the salt, then replace the lid.
Place the Dutch oven back into the oven, and bake for 30 minutes. Do not open the lid. Uncover, bake for 10-15 more minutes, or until the top is crusty and golden brown.
Remove from the oven, transfer bread to a cooling rack, and wait for at least 20 minutes before slicing.