Make the marinade for the kabobs and either place the cubed beef pieces in a zip bag with the marinade for 15 to 45 minutes or up to overnight. While the beef marinades, this is a great time to soak your skewers.
Thread the cubes of meat onto the skewers, alternating with vegetables. If making ahead, store kabobs in a 9x13 baking tray covered with plastic wrap in the refrigerator.
Cook the Kabobs & Veggies in the oven:
Preheat the oven to 375F and line a large baking sheet with parchment paper or foil for easy cleanup.
Remove the beef from the marinade and discard the marinade.
Alternate threading the beef, bell peppers, onions, and mushrooms onto each skewer, about 3 pieces of beef for each kabob.
Place the kabobs on the baking sheet and bake in the preheated oven for 25 to 30 minutes, flipping halfway through, until the beef reaches an internal temperature of 140F to 145F. Total cooking time will vary depending on the thickness of your beef cubes.
Remove the kabobs from the oven and serve with your favorite sides.