In a bowl, mix together the ground meat, chopped parsley, finely chopped onion, and spices until well combined.
Spread the meat mixture evenly over one half of a baking sheet, pressing it into an even layer. Use a knife to make long cuts in the meat to shape it into long kebabs, but don't cut all the way through.
On the other half of the baking sheet, add the vegetables. Cut the onion and sweet peppers into thick strips, slice the mushrooms thickly, and add cherry tomatoes or thick tomato slices.
Sprinkle salt and black pepper over the vegetables, then drizzle olive oil over the vegetables and meat.
Place the pan in a preheated oven at 450°F and bake for 25 minutes, or until the meat is cooked through. If there is a lot of liquid in the pan, carefully drain it into a bowl. You can save the liquid for dipping your kebab sandwich if you'd like. Return the pan to the oven and broil for 5 minutes, keeping a close eye on it until the meat and vegetables are nicely browned.
Remove the pan from the oven and prepare your sandwiches! I love serving mine in buns with fries. Spread mayonnaise inside the bun, then add the beef kebab, roasted vegetables, and fries. Close the bun and cut it in half. You can toast the buns before assembling or toast the finished sandwiches afterward.
You can also use pita bread and hummus instead of mayonnaise, or serve the beef kebab over rice with a side of salad and hummus.