Place burgers on a baking pan and bake for 7 minutes. Flip and bake for an additional 5 minutes.
Prepare veggies by thinly slicing tomato, cucumber, and red onion.
Prepare tzatziki by first slicing a cucumber in half lengthwise and scooping out the seeds. Cut up ½ cup of cucumber chunks, and wrap them in a paper towel to extract excess moisture.
Combine all tzatziki ingredients in a blender, pulsing until just combined. Alternatively, finely chop cucumber, feta, and parsley and stir them together with the other ingredients.
Toast pita in the warm oven for a minute, before assembling the sandwich with the cooked veggie burger and sliced veggies. Drizzle parsley tzatziki over the sandwich before wrapping it closed. Serve immediately.
Recipe by Uproot Kitchen at https://uprootkitchen.com/2016/04/13/greek-veggie-pita-sandwich/