Cook the chicken breast briefly on both sides in a 10-inch oven-safe frying pan with a little bit of vegetable oil. Add the rosemary and garlic cloves to the frying pan and deglaze it with the chicken broth. Cover the frying pan and let everything cook on low heat for 1 hour, making sure to flip the chicken breast over several times while it cooks. Remove the garlic and rosemary from the pan and use 2 forks to pull the cooked chicken.
Pour the flour into a heap on a clean work surface, then make a well in the center. Fill the well with the plain yogurt, baking powder, and salt, then cover the ingredients in the well with flour and knead the mixture by hand until a smooth dough forms. Roll the dough out into a thin circle, spoon an even layer of pizza sauce on top, and sprinkle it with bread crumbs.
Once you've pulled the chicken, set it aside and cook the sliced red onion and chopped broccoli in the frying pan with a little bit of vegetable oil. Season the vegetables with salt & pepper, then add in the halved cherry tomatoes and stir everything together. Add the pulled chicken and cubed cheddar cheese and distribute all of the ingredients evenly throughout the pan.
Place the pizza dough on top of the toppings in the frying pan, making sure the side with the tomato sauce is facing downwards. Lightly press the pizza dough down onto the toppings.
Brush some vegetable oil over the top of the pizza dough, transfer the oven-safe frying pan to the oven, and bake the upside down pizza at 350°F for 30 minutes.
Once the pizza has finished baking, flip it over onto a cutting board or serving dish. Top the upside down pan pizza with plain yogurt and chopped herbs to serve.
