Relish - The Sandwich Bar

You're walking past the offices and government buildings near St James's Park when you spot the line outside Relish, and honestly, you get it immediately. This isn't some corporate chain slinging cardboard on white bread—they're doing proper sandwiches with actual thought behind them. The fillings rotate and change seasonally, but they're always built on quality bread and combinations you wouldn't expect to work but absolutely do. It's the kind of place where people pop in mid-morning just to see what's on that day, and by lunchtime it's rammed with locals who've learned not to sleep on it.