Trim broccoli leaving 1 inch of stem. Cut remaining stems into small slices. Place broccoli and snow peas in a saucepan of boiling water and cook for 1 minute, drain and rinse immediately with cold water then drain well and set aside. Heat a large wok or large skillet over high heat. Add sesame oil, blanched broccoli and snow peas, red onion, red bell pepper, and garlic. Stir-fry for 1 minute. Add the soy sauce and stir-fry 1 minute longer. Remove from heat and stir in sesame seeds.