Almost every table in the five villages is aimed at people who will eat there once — so the useful move is to use the park's own certification list and to shop in La Spezia.
Ristorante Miky, Monterosso al Mare
One of only a handful of restaurants in the whole national park holding the Marchio di Qualità, the park's certification for local and Ligurian supply chains and for water and energy standards. Book ahead; the certified list is short and everyone finds it eventually.
Fuori Rotta and La Lampara, Riomaggiore
Riomaggiore's two park-certified restaurants — the same short list Miky in Monterosso and Alla Marina in Manarola sit on. Five names across five villages is the entire certified field, which tells you how much of the rest is aimed at the one-time visitor.
The daily market in Piazza Cavour, La Spezia
La Spezia runs a daily market in Piazza Cavour under its own municipal regulations — fruit, vegetables, fish, cheese, at city rather than village prices, and twenty minutes by train from Riomaggiore. This is where you assemble a picnic instead of buying one at the trailhead.
Use the park's quality mark as a filter
The Marchio di Qualità 2.0 is awarded for sourcing along local and Ligurian supply chains and for meeting environmental standards, not for cooking — but on this coast a short, checkable list beats a long unchecked one, and the harbour-front alternative is priced for the view.