Make the dressing: In a small container, combine the olive oil, vinegar, garlic, oregano, red pepper flakes, salt, and pepper. Place the shredded lettuce in a small bowl, drizzle over half of the dressing, and toss to combine. Reserve the rest of the dressing.
Start stacking the sandwich! Spread the mustard and mayo on the cut sides of the roll. You can layer up the meats, cheese, vegetables, and condiments any way you like. Save the rest of the dressing to drizzle over the top of your sandwich filling before you put the top half of the roll on. Open very wide, and eat!