Put the steak in a shallow bowl and sprinkle the steak with the chili powder, oregano, cumin, and 3/4 teaspoon garlic salt. Toss gently yet thoroughly in order to coat the steak completely. Let the steak sit 15 minutes in order to absorb the flavors.
Meanwhile, preheat the broiler. Lightly spray the broiler pan and rack with vegetable oil spray.
In a small bowl, stir together the horseradish cream ingredients.
Thread the vegetables and meat onto four 12 inch skewers in alternating order - onion, bell pepper, tomato, and steak. Put the kabobs on the prepared rack.
Broil the kabobs about 4 inches from the heat 4 minutes. Turn the kabobs and broil 3 minutes, or until desired doneness.