1. Sauté onion in olive oil and butter until soft. Add rice and toast 2 minutes.
2. Add wine and stir until absorbed. Add warm stock a ladle at a time, stirring, until rice is creamy and just tender, about 18–20 minutes. Stir in saffron.
3. Off heat, stir in Parmigiano and season. Spread on a sheet pan and chill until firm, at least 2 hours or overnight.
4. Mix 1 beaten egg into the cold risotto. Scoop 2 tbsp portions, press a mozzarella cube into each, and roll into a ball.
5. Dredge in flour, then 2 beaten eggs, then breadcrumbs.
6. Fry at 350°F until deep golden, 3–4 minutes. Drain and salt lightly. Serve with warm marinara.

1. Soak cut potatoes in cold water 30 minutes; drain and dry well.
2. Fry at 300°F until soft but pale, 5–6 minutes. Drain and cool.
3. Fry again at 375°F until crisp and golden, 2–3 minutes.
4. Toss immediately with Pecorino, toasted pepper and a pinch of salt. Serve hot.

Serve the arancini hot, on a small plate or in a paper boat over a spoonful of warm marinara, with a handful of cacio e pepe fries alongside. Finish the fries with an extra dusting of Pecorino and cracked pepper just before handing them out, and serve immediately with a pour of Portalupi Barbera.