Make the broth. In a small saucepan, bring the chicken stock to a boil over medium-high heat. Reduce the heat to medium-low and whisk in the sesame oil, garlic powder, red pepper flakes, peanut butter, and sweet chili sauce until well combined. Remove the saucepan from the heat and stir in the whites of the scallions.
Assemble. Place the instant ramen noodles in a bowl (throw away the seasoning packet) and pour the peanut butter broth over them. Turn and mix the noodles a couple of times to thoroughly coat them in the flavorful broth.
Microwave. Microwave for 1 ½ minutes, stir, and then microwave for an additional 1 minute.
Serve. Serve hot garnished with sesame seeds and the greens of the scallions.