Frittata di Patate e Cipolla alla Molisana

Place the whole potatoes in a pot of cold, well-salted water. Bring to the boil and cook until completely tender throughout — a skewer must meet no resistance at the centre. Drain and leave until cool enough to handle. Peel and crush the flesh coarsely with a fork or the back of a spoon, leaving visible irregular pieces. The crush is done when no whole potato remains but the mass still has texture.

Warm a film of the olive oil in a pan over medium-low heat. Add the sliced onion with a pinch of salt. Cook slowly, stirring occasionally, until the onion is fully collapsed, deep golden, and sweet throughout — 20 to 25 minutes. No sharp or raw smell should remain. Remove from the heat and allow to cool slightly.

In a large bowl, combine the crushed potato, caramelised onion, grated Pecorino, and beaten eggs. Season assertively with salt — the potato's starch dilutes the egg's flavour and this mixture requires more seasoning than a standard vegetable frittata. Mix until cohesive but not uniform. The mixture is ready when no streak of plain egg remains.

Heat the remaining olive oil in a terracotta pan over medium-low heat. Pour in the mixture and press it gently to an even depth of 3 to 4 cm. Cook without disturbance for 8 to 10 minutes. This is where the dish lives or dies: the heat must remain medium-low throughout — high heat burns the surface crust before the thick interior has any chance to set. The frittata is ready to flip when the edges are visibly set and golden, the top surface has lost its liquid sheen, and the underside releases cleanly from the pan when the edge is lifted with a spatula.

Slide the frittata onto a flat plate. Invert the pan over the plate and flip both together in one decisive movement so the frittata returns to the pan, uncooked side down. Cook the second side for a further 8 to 10 minutes over medium-low heat. The frittata is done when both sides are deep golden, the interior yields under gentle pressure without feeling liquid, and the whole cake holds its shape when the pan is tilted.

Slide onto a board or plate and allow to rest for at least 5 minutes before cutting into wedges. The frittata is equally correct served warm or at room temperature; the flavour develops and the interior firms further over the first hour after cooking.