I was going to say the special purpose of green tomatoes, but once you've seen The Jerk you can never say "special purpose" again. So the highest purpose of green tomatoes is a gratin. They're fine pickled or fried, but in a gratin they reach their apotheosis, their verdant tartness marrying the rich creamy sauce so perfectly.
The link to the recipe I worked from is in the previous post, but I changed it enough that I'm including my own version here. I tripled the recipe, using scallions instead of shallots, and breadcrumbs from homemade bread instead of panko, and lots more breadcrumbs than originally called for. In other words it's a bigger bolder recipe. Not to imply that the original recipe is dinky and timid.
Green Tomato Gratin, Chez Dream Kitchen
This will feed 10 people if they like it. And they will like it.
3 lbs green tomatoes
For breadcrumb topping:
2 1/2 C breadcrumbs (diced stale bread)
Kosher or sea salt
3 T olive oil
For Mornay sauce:
4 1/2 T butter
1/3 cup finely chopped scallions
6 T flour
2 1/4 C heavy cream
2 t Kosher or sea salt (less if you use regular salt)
3/4 C fresh grated parmesan or pecorino
1/4 t fresh grated nutmeg
You can cut the tomatoes a few hours ahead of time, and you can also make the sauce ahead of time. Just warm the sauce up in the microwave a little before mixing it with the tomatoes.
Preheat oven to 450.
Mix all the ingredients for the breadcrumb topping together and set aside.
To make the Mornay, put the butter and scallions in a medium saucepan and saute over medium heat for about five minutes. Add the flour and stir for about 1 minute. Whisk in the cream then add the cheese, salt and nutmeg. Continue whisking until the sauce thickens, then take it off the heat.
Spread the tomatoes evenly between two large shallow glass or ceramic baking dishes. Pour the sauce over the tomatoes. Sprinkle the breadcrumb topping evenly on top then place the dishes in the oven.
Bake for 15 minutes or until the sauce is bubbling and the breadcrumbs are golden brown.
For selfish reasons, I'm sad that this disappeared so quickly at the dinner party. I did take three or four slices that were left on a child's plate . . . is that pathetic?