Heat a tablespoon of vegetable oil in a large nonstick skillet over medium heat. Add the dumplings in a single layer. Cook for 2 to 3 minutes per side, until golden-brown. Add water to the skillet until it covers the dumplings by about a third. Cover the skillet with a lid and cook until the dumplings are cooked through, about 5-8 minutes. Transfer dumplings to a plate. Wipe skillet clean. Heat another tablespoon vegetable oil in the skillet over medium-high heat. Add the broccoli and bell peppers, stirring occasionally, until crisp-tender, 8 to 10 minutes. Add the garlic and the ginger and cook until fragrant, about 1 minute. Stir in sesame oil Sriracha, soy sauce, honey and rice vinegar. Bring to simmer and cook, stirring gently, until the mixture reduces down slightly. Return the cooked dumplings to the skillet and toss with vegetables. Top with green onions and toasted sesame seeds before serving.