Turn grill to medium-high and let heat.

Place the chicken in a baking dish and cover with half a bottle of the caesars dressing. Let sit while you prep the other items.

Rinse the lettuce carefully and then slice in half, leaving the stems in-tact. Lay them, cut side up, on a baking sheet and drizzle with lemon juice, olive oil and then generously salt and pepper.

(If you're going to do onions too, drizzle them with just a tiny bit of olive oil).

Cook the chicken on the grill until cooked through (if it's done before everything else, put it on a plate and cover with tinfoil to keep warm until everything's ready).

Cook the onions about 7-10 minutes, until browned in spots. Add the lettuce to the grill and cook about 1 minute on each side.

Plate the lettuce, chicken, and onions. Add croutons, top with Parmesan cheese, and, if desired, top with additional dressing (I obviously had more dressing, but other more adult-ish adults refrained).