In a large bowl, whisk together soy sauce, brown sugar, garlic, ginger, sesame oil; set aside.
Take 6 Tablespoons of the marinade mixture out of the big bowl and set into a small separate bowl (you will have 2 bowls of marinade).
Heat olive oil in a large skillet over medium high heat. Add the garlic, asparagus, carrots, bell pepper and zucchini. Saute, stirring occasionally, just until crisp-tender, about 3 to 4 minutes; season with salt and pepper, to taste. Set aside.
Cut beef into thin serving size pieces, pounded to 1/4-inch thickness, if needed. Put beef in a bowl and liberally brush largest bowl of marinade on and let marinate in the refrigerator for at least 30 minutes. (The longer it marinates, the better!)
After the meat has marinated, working one at a time, top each beef slice with each vegetable, roll up and secure with a toothpick.
In the beef marinade that's left over from the marinating process, liberally brush the mixture onto each of the roll ups.
Preheat a gas or charcoal grill to medium heat. Add roll ups to the grill, seam-side down, and cook until browned, about 2-3 minutes per side.
After you remove these from the grill, brush the marinade that was not used that was set aside on top of your cooked roll ups.
Garnish with cilantro and sesame seeds. Serve immediately.