Preheat oven to 350.
Line a baking tray with parchment and place the pita on it.
Slather the pita with ketchup/marinara/pesto.
Add vegetables and sprinkle half the cheese on top. Add salt at this stage if desired.
Bake for 7-8 minutes. Sprinkle the remaining cheese on top carefully, and bake for 2 more minutes.
Let it cool a bit before using a serrated knife to cut the pita into squares.