ah now we’re talking, I am normally very happy with my sandwiches being something of a connysewer in the breaded snackery department. Sandwiches are not something to be made and packaged in the morning, squashed into your bag and then crammed into the shared use fridge at work or (shudders) sat next to your PC til lunch time. Buff butties should be made and eaten within 20mins or you risk salad induced sogging of the bread. Well prepared sarnies can use the primary filling of choice and the lettuce to buffer tomatoes and cucumber keeping your lunchbox in reasonable condition but this is still a risk I’d rather not run. Take bread, filling, salad and any spreads pickles condiments etc and prepare on site, only way to be sure.
But I had the remnants of yesterdays roast for lunch today (7/10 not 100% on roasties done in lard, top class gravy tho and sweet potato mash was a nice change)