But how do you make a roast beef sandwich at home that tastes like it came straight from the deli? Tasting Table spoke with an expert — Ron Didner, the owner of Mookie's NY Deli — to find out.

My No. 6 (roast beef and provolone) 7-inch sub cost me $12.36, or about $1.77 an inch. My Jersey Mike's sandwich reminded me of one from a mom-and-pop deli. The roast beef piled onto my Jersey ...