In a small bowl, combine honey, soy sauce, rice vinegar, and if desired, add cornstarch. Whisk until smooth and set aside.
In a large skillet, heat one tablespoon of olive oil over medium-high heat. Once hot, add the sliced chicken sausage and sauté until browned, approximately 5-7 minutes. Remove the sausage from the skillet and set aside.
In the same skillet, add the remaining tablespoon of olive oil and toss in the broccoli florets. Sauté for about 4-5 minutes until the broccoli is bright green and slightly tender.
Next, add the shrimp to the skillet with the broccoli and cook for an additional 3-4 minutes or until the shrimp turn pink and are opaque.
Stir the cooked sausage back into the skillet, and add the minced garlic & red pepper flakes (if using). Sauté until fragrant, around 1 minute.
Pour the honey garlic sauce over the shrimp and sausage mixture. Stir to coat evenly while cooking for another 2 minutes until the sauce thickens slightly.
Season the dish with salt and pepper to taste, and serve hot, garnished with sesame seeds and chopped green onions.