Shaker Turnip Souffle

2 lbs turnips
1 tablespoon sugar
1 onion, sliced
3 tablespoons butter
1 (10 ounce) can cream of mushroom soup
3/4 teaspoon salt
1/2 teaspoon pepper
3 eggs, well beaten
1 cup buttered cracker crumbs

Peel and cut turnips into pieces and boil with onion and sugar until tender. Drain well.
Mash the turnip mixture and mix with the remaining ingredients, except the cracker crumbs; sprinkle on top of mix.
Place in a buttered dish and bake at 350 degrees for 30 minutes or until firm.