In a large mixing bowl, stir together the flour, yeast, and salt. Then add the beer and olive oil, and stir until a stiff, shaggy dough develops -- about 30 seconds. Tip the dough onto a non-floured surface, and knead, by hand, until the dough becomes smooth and elastic -- about 10 minutes. Transfer the dough to a large greased bowl, flip the dough to grease its other side, and then cover the bowl with clingfilm or a damp towel. Let the dough rise in a warm location until doubled in volume -- 90 minutes to 2 hours.
When the dough has doubled in volume, punch it down, pat it out, and form it into a tight ball. Pinch the seam to seal it. Then place the ball seam side down in a greased bowl. Dust the top with flour. Cover loosely with clingfilm or a dry tea towel, and let rise in a warm spot until doubled in volume -- usually 30 to 45 minutes.
While the dough is rising, place a heavy, oven-proof pot (covered with its lid) on the lower-third level of the oven. Preheat the oven to 450°F.
When the dough is ready, sprinkle its top with flour or cornmeal. Then remove the ripping-hot pot from the oven, and place it on your protected work surface. Flip the dough into the pot, its seam side now facing up. Cover the pot with its hot lid, and return it to the oven. Bake for exactly 30 minutes. Then uncover the pot, lower the oven temperature to 400°F, and bake until the crust browns and splits at the seam -- 10-15 minutes. Transfer the bread to a wire rack. Cool completely before slicing.