Set oven to 375F.
Cut your vegetables into thin strips/pieces.
Slice flank steak in half to make it thinner, then cut into several strips.
In a bowl, mix ingredients of the marinade together. Set aside about 1/4 cup marinade for brushing after baking. Add steak strips and marinate for at least 20 minutes.
Take a strip of steak and place it flat down on a plate or table. Add zucchini, 1 asparagus spear, carrots, bell pepper and kale. Roll it up and repeat until all steak has been used. If needed, you can use a toothpick to secure the rolls.
Sear the rolls in a nonstick skillet for about 1 minute in order to “cook close” the rolls. Place the rolls on a baking rack and bake for 15 minutes at 375F. Brush the baked steak rolls with the marinade that you set aside.