Heat olive oil in a non-sticky skillet on medium heat till hot. Add onion and potato, stir constantly till onion turns yellow, in 4 to 5 minutes. Add garlic and cumin and stir for another 2 to 3 minutes, till garlic fragrant well and cumin is mixed well with potato. Add in white wine vinegar, sugar and black olive, give it a stir. Then add in tomato, cayenne powder, paprika powder, oregano, parsley and salt. Keep stir until everything is mixed well.
Spread the mixture in a baking dish by spoon, place almond on top, bake in the oven for 25 to 30 minutes, until potato turns golden brown and most liquid has been absorbed.
Mix all the ingredients for the Tzatziki and set aside.
Serve the baked potato when chilled down a bit or cold, with Tzatziki sauce.