Don't let the idea of making your own pizza dough scare you. This is a fast, no-fail recipe that's fun to make, and any vegetables your family enjoys are suitable as a stuffing. Pita pockets, found at your grocery store, may also be used instead of pizza dough.
Preheat the oven to 375 degrees.
To make the dough, sprinkle the yeast in the water and then mix in the oil. Place the flour and oregano in a mixing bowl and make a well in the center. Add the yeast mixture to the well. Using a wooden spoon or your fingers, mix until the dough forms a ball. Place on a floured work surface and knead for 5 minutes. Place the dough in a clean bowl that has been lightly coated with olive oil and set aside in a draft-free, warm place while preparing the vegetables.
In a large skillet, heat the oil, then saute the peppers, zucchini, cauliflower, tomatoes, scallions and oregano for 5 minutes. Set aside.
Roll out the pizza dough into an 11-by-16-inch rectangle. Move to a cookie sheet. Sprinkle the mozzarella lengthwise down one side of the dough. Top with the vegetables, then sprinkle on the remaining cheese. Brush the edge of the dough with cold water. Fold the other half of the dough over and press the edges to seal. Brush the top with olive oil before baking in a 375-degree oven for 15 minutes. Cut into pieces and serve. Makes 4 to 6 servings.