In a large skillet, sweat onions in olive oil over lowest possible heat, stirring frequently, for 2 to 3 hours or until very soft, golden brown, and marmaladelike. Add mangoes and continue cooking for about 10 minutes. Season very generously with pepper, remove from heat, and set aside to cool.
Meanwhile, in another skillet, sauté shallots in olive oil, also over lowest possible heat, for about 30 minutes. Add curry powder, stir in well, and continue cooking for 5 more minutes. Remove from heat and set aside to cool.
While onions and shallots are cooking, bring salted water to a boil and cook potatoes until done (about 20 minutes). Drain and mash with
Divide yogurt evenly between two bowls and mix half the remaining crème fraîche or sour cream into each one. Stir shallots and a little of their cooking oil into one bowl. Stir tomatoes into the other and season with a few drops of Tabasco sauce. Salt both mixtures to taste, then refrigerate.
Remove gyoza or wonton wrappers from refrigerator, cover with a damp, clean cloth to keep them from drying out, then begin filling half of them with onion and mango mixture and half of them with potato mixture. To do this, place a small amount of filling in the middle of each wrapper, then fold over (gyoza wrappers into half-moon shapes, wonton wrappers into triangles) and crimp edges lightly.
Heat peanut oil to 375°, then fry gyozas or wontons in small batches until golden brown, draining on paper towels as done. Serve with chilled dipping sauces on the side.
© 1992 Colman Andrews. All rights reserved.