Make the sauce: Put the soy sauce, fish sauce, plum wine, sugar, garlic, jalapeno, ginger, lemongrass, and water in a bowl and stir together; set aside.
While you make the vegetables, pour enough oil to submerge the snapper into a wide, deep, heavy-bottomed pot. You will need at least a quart, depending on the width of the pot and the thickness of the fish. Heat the pot over medium-high heat to 370 degrees F.
Make the vegetables: Heat 2 tablespoons canola oil in a skillet over medium-high heat. Add the sliced ginger and sausage and cook until the sausage begins to give off its fat, about 5 minutes. Add the mushrooms and cook until they begin to give off their liquid, adding more oil if necessary. Add the tomatoes, scallions, carrot, leek, and chile, and cook until just soft, about 2 to 3 minutes. Remove the pan from the heat, cover, and keep the vegetables warm.
Fry the fish: Score the snapper 4 times from top to belly, starting about 3 inches behind the head and making the last slash about 2 inches from the tail; take care not to cut into the flesh. When the oil is almost hot enough, dredge the snapper in the flour, shaking off any excess. Skewer the fish from head to tail with a metal skewer, curving the fish as needed. Slowly carefully add the fish to the pot and fry until cooked through and moist at the bone on the head end, approximately 10 to 15 minutes.
To serve: Spread some sauce onto a fish platter and place the fish on top; spoon the vegetables over the fish. Present at the table, cutting individual portions there, and garnishing with pea sprouts. Serve the extra sauce on the side.
Recipe courtesy of Chef Laurent Tourondel