Cork people are smug about their food and the rest of Ireland will quietly agree they have a right to be. The city is also small enough that the best places are walkable from each other. Here is a real local's plan.
Breakfast: the Farmgate Cafe inside the English Market
Climb the stairs at the back of the English Market and you find the Farmgate Cafe, on a balcony looking down at the stalls below. Order the white pudding and eggs, or the smoked haddock if it is on. The coffee is decent, the prices are honest, and you can shop on your way back out.
Lunch from the market itself
Skip restaurants for lunch. Buy a baguette from the bakery counter, pick a hunk of Gubbeen or Cashel Blue from the cheese counter, get a few slices of properly cured ham from On the Pig's Back, sit on the bench in Bishop Lucey Park around the corner. That is what locals do on a sunny day.
Mid-afternoon: 3FE on Patrick's Street
If you only do one coffee in Cork, do it at 3FE. The roastery is Dublin-based but the Cork branch is among the best coffee bars in the country.
Dinner option 1: Paradiso, vegetarian
Paradiso, on Lancaster Quay, has been run by Denis Cotter for thirty-something years and has been turning out the best vegetarian food in the country for all of them. Reservations needed. The four-course tasting menu is not cheap, but it is what most Corkonians will recommend if you ask for one special meal.
Dinner option 2: Goldie
Goldie, on Oliver Plunkett Street, is the more recent darling. Sustainable seafood, small plates, reasonable prices for the quality. They do a good wine list. Book ahead.
Dinner option 3: Market Lane
If you have not booked anything and you turn up at seven, walk to Market Lane on Oliver Plunkett. They take walk-ins, the food is reliable, and the room is nicer than most places of its price range.
Pub food worth the detour
The Bierhaus, the Franciscan Well brewery and Sin E (with the accent) all do better-than-average pub food. Sin E in particular has trad sessions most evenings and you can eat properly between sets.
One trip outside the city
If you have a spare half-day, drive to Ballymaloe in East Cork. Forty five minutes from the city. The cafe at Ballymaloe House does the kind of lunch that has shaped Irish restaurant cooking for fifty years. The shop next door at the cookery school sells the same bread, jam and cheese you ate.