Chicken Stir Fry - Happiness in a Skillet!

Ingredients

• 2-3 Tablespoons butter, divided
• ½ Medium onion (thinly sliced)
• 1 Large yellow bell pepper (diced into ¾ inch cubes (about 2 cups))
• 2 Cups sliced mushrooms
• 2 Cups diced zucchini (about ¾ inch cubes)
• 2 Cups frozen baby broccoli florets (thawed, if possible)
• 6 Tablespoons soy sauce, divided (I prefer Kikkoman brand)
• 1 tablespoon roasted sesame seeds
• 2 Tablespoons oil (vegetable, peanut, olive -- whatever you prefer)
• 4 Medium boneless, skinless chicken breasts (cut into 1 inch cubes)
• ½ lemon
• ½ teaspoon black pepper
• 1 tablespoon FISH SAUCE ... Yes!
• 1 cup chicken broth
• 2 Tablespoons cornstarch
• ½ Teaspoons sesame oil