Make spaghetti based on package instructions. Reserve ½ cup pasta water before straining.
Whisk soy sauce, brown sugar, and sesame oil in a small bowl – set aside.
Heat 1 tablespoon oil in a large pan. Add bell peppers and carrots. Stir frequently until brown and tender. Add broccoli and cook for an additional 2 minutes. Remove veggies and set aside.
Melt butter in the pan with remaining olive oil. Add garlic and red pepper flakes (if using) and saute for about 3 to 5 minutes.
Add cooked pasta, veggies and sauce to pan and mix together. Add pasta water to achieve desired consistency. Top with parsley and serve.
Michele L. Seattle, WA
Judy H. Marblehead, MA