Place garlic and onion in a food processor and process until onion turns to juice. In a small mixing bowl, combine processed garlic and onion, ginger, red pepper powder, and sugar. Toss with kale and make sure all pieces are coated with seasoning. Add scallions and toss again. Spoon kale mixture into glass jars and cover. Store at room temperature overnight to ferment. Chill. Serve.