Heat sesame oil in a saucepan over medium heat. Cook and stir green onions, sesame seeds, garlic, and red pepper flakes in hot oil until fragrant and onions start to soften, 2 to 3 minutes. Stir chicken broth, tamari sauce, vinegar, sugar, and curry powder into onion mixture; bring to a simmer. Whisk in almond butter and stir until thickened, about 5 minutes.