Whisk together Korean Sauce in a medium bowl. Set aside.
Brown beef and onion in a large skillet over medium-high heat. Add garlic and ginger and sauté an additional 30 seconds. Drain off any excess fat.
Add Korean Sauce and bring to a boil. Reduce to a simmer for 5-10 minutes or until reduced and thickened. Taste and add chili paste for spicier, brown sugar for sweeter. Remove from skillet but do not wipe out.
Add one teaspoon olive oil and heat over medium-high heat. Add zucchini and red bell peppers (or other desired vegetables) and stir fry 2-3 minutes or to your desired crisp-tenderness.
Layer 4 bowls with rice and top with Korean beef and vegetables.
Notes
Use 3 tablespoons brown sugar if using 3 tablespoons Gochujang. Use 2 tablespoons brown sugar if using 2 tablespoons Gochujang.
You can substitute or add your favorite stir fry vegetables to this meal.