Whisk the semola rimacinata, bread flour, yeast, and salt in a 4-quart / 4 L bowl. Add the lukewarm water, honey, and olive oil, then mix with a wet hand or a dough hook for 2 minutes, until no dry flour remains.
Knead on an unfloured counter for 10 minutes, or 8 minutes on medium-low in a stand mixer, until the dough is smooth and springs back slowly when poked. It stays sticky for the first 5 minutes. Resist adding flour and lift it with a bench scraper instead.
Shape the dough into a ball and place it in a lightly oiled bowl. Cover and let it rise at 24 C / 75 F for 90 minutes, until doubled in size.
Divide the dough into two pieces of about 450 g each. Roll each piece on an unfloured counter into a rope about 55 cm / 22 inches long and 3 cm thick, working from the center outward.
Spread the sesame seeds on a rimmed plate. Brush each rope lightly with water, roll it through the seeds until fully coated, then wind it into a tight spiral and tuck the end underneath. Set both coils on a parchment-lined 33 x 46 cm / 13 x 18 inch sheet pan, about 10 cm / 4 inches apart.
Cover the loaves loosely with a towel and proof for 45 minutes, until puffy and a fingertip dent springs back slowly. For the last 20 minutes, set a rack in the middle, put a 20 cm / 8-inch metal baking pan on the lowest rack, and heat the oven to 220 C / 425 F.
Slide the sheet pan onto the middle rack, pour the boiling water into the hot metal pan, and close the door quickly. Bake for 15 minutes, then lower the heat to 200 C / 390 F and bake 20 minutes more, until the crust is deep golden and the center of the coil reads 205 F / 96 C.
Move the loaves to a wire rack and cool for at least 30 minutes before slicing, so the crumb finishes setting.