While the wings marinate, prepare the gochujang sauce. In a small saucepan over medium heat, whisk together the gochujang, tomato paste, honey, brown sugar, soy sauce, sesame oil, and lime juice until all the ingredients are incorporated, and the sugar dissolves, about 5 minutes. Remove from heat and let cool. The sauce can be made up to a week ahead of time and refrigerated in an airtight container until ready to use.
Let the wings sit at room temperature for 30 minutes, then toss with the cornstarch. Meanwhile, pour enough vegetable oil into a large, deep cast-iron pan to reach 1 inch (2.5 cm) up the side of the pan.
Heat the oil to 350°F (177°C) and, working in batches, shake off any excess cornstarch and fry the chicken wings, turning occasionally, until golden brown all over and cooked through, 6 to 10 minutes. Move to a paper towel-lined plate to drain. Allow the oil to return to temperature before cooking the remaining batches.
To serve, reheat the sauce, if necessary, and toss with the freshly fried chicken wings. Serve topped with sesame seeds and scallions.