Heat 1 tablespoon of the oil in a large soup pot. Add the onions, garlic, ginger and red pepper flakes to the pot and cook stirring occasionally for 5 minutes or so, long enough for everything to get fragrant.
Add the red curry paste and stir it into the onion mixture. Add the chicken stock and stir until the paste is well blended. Bring the mixture up to a boil. Reduce the heat and cook, covered for 15 - 20 minutes.
Uncover the pot and add the vegetables. Simmer for a few minutes...about the time it takes to brown the pot stickers.
In a large skillet heat the remaining oil over medium high heat. Add the pot stickers and cook until the flatter side is golden brown.Drop the browned pot stickers into the soup and continue to cook for another 5 minutes or so.
Divide the pot stickers into 4 soup bowls. Ladle the rest of the soup evenly among the bowls. Garnish with sesame oil, sriracha sauce and the scallions. Serve.