Supplì al telefono are Rome's answer to Sicily's arancini—oblong, egg-shaped rice croquettes with a heart of molten mozzarella that, when bitten into, stretches into long telephone-wire-like strings of cheese (hence 'al telefono'—the stretching cheese mimics pulling apart a telephone receiver from its cord). While arancini are Sicily's and supplì are Rome's, the two have distinct identities: supplì are smaller, oval rather than round, and always contain the mozzarella 'telephone wire' as their defining feature. The rice is cooked in a light tomato-based ragù (not the saffron broth of arancini), cooled, and mixed with beaten egg and grated Parmigiano or Pecorino. A portion of the rice is shaped around a cube of fior di latte mozzarella, formed into an elongated egg shape, rolled in breadcrumbs, and deep-fried at 170-175°C until golden-brown and crisp. The moment of truth comes at the first bite: the crust shatters, the rice inside is moist and tomatoey, and the mozzarella at the centre has melted into a stretchy, gooey pool that pulls into long strings when the supplì is broken open. This cheese stretch is not merely aesthetic—it's the textural and flavour payoff that makes the supplì more than just a fried rice ball. Supplì are the classic Roman snack, sold at pizzerie al taglio (pizza by the slice shops) and rosticcerie, typically consumed as an aperitivo or merenda (afternoon snack) while standing at the counter. They are always eaten hot—cold supplì lose the cheese stretch and the textural contrast. Classic supplì are al ragù (with a meat-and-tomato rice base), but modern Roman pizzerie offer creative variations.
Rice cooked in tomato ragù, formed around a cube of mozzarella. Oval/egg shape (not round like arancini). Breaded and fried at 170-175°C. The mozzarella must stretch when bitten. Serve immediately while hot. Eat the cheese stretch—that's the point.
The mozzarella cube should be cold (or even frozen) when encased in the rice—this gives it time to melt during frying without the rice burning. Double-breading produces a crispier shell. The rice should be cooled completely before forming. Fry in small batches to maintain oil temperature.
Not achieving the cheese stretch (mozzarella must be at the core). Serving cold or lukewarm. Making them too large (should be manageable in a few bites). Under-frying (no crisp crust). Using dried-out mozzarella (won't stretch).
Ada Boni, La Cucina Romana; Rachel Roddy, Five Quarters