I make Tri-Tip at least once a month from May through October. I don’t have too much trouble getting Tri-tip in The City but figuring out how to grill in Manhattan was/is a PITA. In addition to the classic ranch beans, bread, and pico, I do grilled frites. Take russets, scrub ‘em, nuke ‘em to 2/3rds done, cut them in…