Start with romaine, it's mildness lets other flavors shine. Balance it with parmesan, this rich, smooth cheese contrasts with romaine's low-key flavor. Accent it with fresh cracked pepper, it's a subtle seasoning, so it adds just the right touch of heat. Bring it all together with lemon juice vinaigrette, A slightly tart oil-based dressing like this one is all you need to integrate the dish. A stronger one would overwhelm the other ingredients.
If you like mild, crunch greens like romaine, try these: bibb lettuce, belgian endive, red-leaf lettuce and bok choy.