Bring 5½ cups/1.3L of water to a boil in a wide pan on medium-high heat, then season with ¾ tsp salt. Add the bucatini and cook for 9 minutes (or per package instructions) until al dente, stirring every now and then so they don’t stick together or to the bottom of the pan, and to ensure they are submerged. Drain, reserving all the cooking water (you should have about 2¼ cups/520ml—if not, top up with a little hot water).

Melt the butter in a large, high-sided, nonstick sauté pan on high heat until bubbling, then add the 1 tbsp za’atar and pepper and cook for 1 minute, stirring, until fragrant. Add the reserved cooking water, bring to a rapid boil, and cook for 5 minutes, until silky and reduced a little. Add the pasta and stir vigorously into the sauce. Add the Parmesan in two batches, continuing to stir vigorously as you go and waiting until the first half has melted before adding the next. Once the Parmesan has all melted, add the pecorino, continuing to stir until it has also melted and the sauce is smooth and silky.

Transfer the pasta to a lipped platter and finish with the olive oil, marjoram (if using), remaining 1½ tsp za’atar, and a small pinch of salt. Serve at once.