PREHEAT oven to 350ºF.
WHISK eggs, water, and olive oil in a large bowl. Add baking mix; combine well. Stir in apple cider vinegar. Let dough sit and thicken for 4 minutes.
GREASE your hands with olive oil and roll dough into one large ball, flatten out onto a greased baking sheet.
ADD halved cherry tomatoes, pressing them into the dough and then add sliced onions. Season the entire dough with oregano, salt, pepper, and a drizzle of olive oil.
BAKE for 18-20 minutes. Broil at the last minute. Serve and enjoy!