The best fries in Lima? Many restaurants take pride in their fries, especially in using “native” species, which is odd as they are all native (Peru is the origin of the potato). But, more to the point, restaurants are branching out instead of just using the usual yellow potato. The common Peruvian yellow potato is small and is not well suited to fries. This makes the efforts of Juicy Lucy and Bao more impressive. Another fashionable potato these days is the Huayro. Most places make good fries as fries are an integral part of two of the most popular dishes: lomo saltado and salchipapas.
Here are a few of the places that I recommend:
Osso: Yes, I think they might be the best. They are made from large yellow potatoes. The fries are big, hot, crunchy, hard, floury, yellow like out of crayon box, and screaming for mushroom sauce!
Quisso: The fries are slim like that place with the arches. The fries are fresh cut like in Five Guys. They use the Huayro potato. When the potato is fresh cut and dropped in the fryer, the liquid escapes like firecracker champagne bubbles all along the surface of the fries. Bonus is that these fries are then covered in cheese.
Bao?: small wedges of round Peruvian yellow potatoes fried hard to give them that oven roasted feel.
Cafe A Bistro: I’m told that this places does great fries. Possibly one of the most charming things about this cafe is that it it located next to a gas station.
Merito: They make yuca fries. The yuca/cassava is a root but if soaked ahead of time, it makes a great fry. The ones are Merito are enormous. 
Cosme: “Col” salad at Cosme. This large (larger than most main courses) salad is served on a ten inch wide plate and is large enough for a main dish or to be shared as an appetizer. It is listed as an appetizer on the menu at Cosme. The salad has raw shredded red cabbage, alfalfa, cashews, hearts of palm, artichoke, cherry tomatoes, lettuce, avocado, and the dressing is a yogurt based dressing so you feel healthy when eating it.
Osso: Although Osso is a steak house, there is a selection of salads including an attractive wedge salad (in real life, in the close up above, the wedges rise like the Andes covered in mint green and dusted with bacon and candied pecans). The second salad mentioned, “salad #3” contains tiny deep fried cheese balls. I recommend keeping the dressing on the side, and foregoing the song and dance of the waiter pouring and tossing, so that you can enjoy the fried cheese “croutons”. The salad is called #3 because on the old menu, it was the #3 (at least, I think that’s why).
Cafe A Bistro: The head salad is like an iceberg wedge salad, but you get all and not only the wedge (the photo doesn’t do the salad justice as the salad is more impressive when viewed in profile).
Pardos Chicken: Has a lettuce salad but I like their “cooked salad” with cooked carrots, beets, beans, and avocado. But, we were talking about lettuce.