Any type of steak or roast can be used for this recipe. If you can cut the beef into 1" cubes, you will be successful.
Combine olive oil, soy sauce, Teriyaki sauce, honey, garlic and black pepper in a bowl or large plastic bag. Add the cubed beef and the mushrooms and marinate for at least three hours (overnight in the refrigerator is okay also).
When the ingredients have been marinated, start by cooking the quinoa so it is done about the same time as the kabobs.
Remove mushrooms and beef from marinade and thread them onto a skewer, along with the pepper and onion (and tomatoes if you are using them).
Heat the marinade and add a tsp of corn starch to thicken it.
Cook the skewered ingredients on the grill for ten or fifteen minutes. Turn them a few times, and brush marinade on them each time you turn them. Another option is to brush BBQ sauce on, but I would not recommend it. You already have a lot of flavors going on here. However, if you really like the BBQ sauce option, then I suggest that you do not marinade the meat and mushrooms.
Place the quinoa on a serving platter and pile the skewers on top. ENJOY!