WHEN FRIENDS VISIT Flynn McGarry’s restaurant, Gem, on the Lower East Side, he will often encourage them to check out the unassuming tailor with the tiny storefront two doors down. That’s where, for the past five years, Ramón Nuñez has been making the chef’s custom pants, shirts, and suits at prices he says are “way too cheap, always.” Before the pandemic, the tailor shop was relatively quiet, the clientele comprising mostly local residents and other people, like McGarry, who had heard about it through friends. Now, “everyone is going to him,” says McGarry. Most days, fashion editors and creative directors wait outside for their turn at Nuñez’s attentions. Where foot traffic to Gem used to bring new clients into the shop, now, McGarry jokes, “friends will only come say hi…