Add olive oil to cast iron skillet over medium-high heat. Generously salt and pepper short ribs and sear in pan.
Add ribs and the remaining ‘rib’ ingredients to a slow cooker. Make sure ribs are nestled down into the liquid. Cook on low for 8 hours, or high for 3-4 hours. When ribs are cooked and falling off the bone, remove from slow cooker and let rest.
Preheat oven to 400 degrees. Stretch and fit pizza dough into a baking sheet. Brush with drippings from the slow cooker and season with oregano. Bake until lightly golden brown, about 5 minutes.
Using the same cast iron skillet, brown mushrooms, season with salt and pepper and set aside.
Remove pre-cooked pizza crust from oven and spread with laughing cow cheese. Layer mushrooms, onions (from slow cooker) and shredded short ribs on flatbread until completely covered, keeping ½ inch border on all sides. Top with parmesan cheese. Bake another 10 minutes, until cheese has melted.
While your flatbread is baking, finely chop all gremolata ingredients together and set aside. Top flatbread with gremolata and serve.