How can I incorporate brown lettuce into something appetizing?

Brown lettuce may or may not be harmful to you, it depends on how far gone it is.

We get a lot of questions on this forum asking about how to use ingredients which may be past their prime, and the advice is almost always not to try - mixing bad ingredients with good ingredients is almost always going to ruin your good ingredients and waste time and money.

So don't try to incorporate it into anything, either make a dish that can stand on its own or throw it away. If it's not smelly, or slimy, or looks rotting then taste it. Try each type of leaf in each bag, if they taste ok then you could try making something out of it.

Personally I'd chuck it. I wouldn't want to be served brown lettuce, and I wouldn't serve it to anyone else.

I have a slow baked fish recipe that will be just perfect for you. I found it about 30 years ago in the New York Times Magazine.

Cut the lettuce into julienne strips.Rinse it, shake but leave it wet.

Place a bed of the lettuce it in a baking pan with sliced aromatics such as onion, shallot or garlic .

Sprinkle the lettuce lightly with water or white vermouth.

Lay thin white fish filets on the lettuce bed. White fish or orange roughy work well.Season to taste. Dot with butter if you like but you can skip that if you want to avoid the fat.

Cover the pan with foil and seal the edges.

Bake in a low oven,around 200-225 F for about 40 minutes.

Remove the fish and discard the lettuce/aromatic base.

I topped it with lemon and capers .

Essentially the julienned lettuce acts as a steaming base. Because you discard it after cooking it doesn't matter what it looks like.

I used iceberg and romaine. You need to be mindful if your lettuces are in the bitter range such as arugula or rocket. Watercress would be good, though.