1, To make the tomato sauce, in a saucepan, heat the oil over medium heat. Add the shallots and cook, stirring occasionally, for about 3 minutes, until light golden brown. Add garlic and chiles and cook, stirring occasionally, 45 seconds more, until aromatic. Stir in the rice wine, tomatoes, and stock and bring to a boil. Decrease the heat so the mixture is at a gentle simmer and simmer, stirring occasionally, for 45 minutes, to blend the flavors.
2, Remove the sauce from the heat and stir in the fish sauce. Let cool slightly, then transfer to a blender and process until smooth. Keep warm. (The sauce can be made a day ahead, cooled, covered, and refrigerated; reheat before using.)
3, To form the wontons, place a wonton wrapper on a work surface. Lightly brush the edges of the wrapper with water and place 1 teaspoon of the filling in the center. Top with a second wonton wrapper, pressing to enclose the filling and form a square, like a ravioli. Force out as much air as possible as you seal the edges to prevent the wontons from puffing up when you fry them. Transfer the finished wontons to a baking sheet or large tray lightly dusted with cornstarch. Repeat until you have used up all of the filling.
4, Pour the oil to a depth of 2 inches into a wok or high-sided pot and heat over high heat to 375°F on a deep-frying thermometer. Line a rimmed baking sheet with paper towels and place near the stove. Place a second rimmed baking sheet alongside. Preheat the oven to 200°F.
5, When the oil is ready, add one-third of wontons to the oil and fry for 3 minutes, until deep golden brown and crisp. Using a spider or slotted spoon, transfer to the paper towel–lined baking sheet to drain briefly, then transfer to the second sheet pan and keep warm in the oven. Repeat with remaining wontons in two batches, always allowing the oil to return to temperature between batches.
6, Arrange the wontons on a platter and serve immediately, accompanied by the tomato sauce. Dip the wontons in the sauce and eat.