Preheat a pizza stone (or rimless baking sheet) in a 450° oven 30 to 40 minutes. Mix fromage blanc, lemon zest, and pepper together and set aside.
Heat oil in a large frying pan over medium heat. Add garlic and green onions and cook until softened and fragrant, about 5 minutes. Add dandelion greens, arugula, salt, and lemon juice and cook until barely wilted, about 1 minute. Drain excess liquid.
Divide pizza dough in half and roll out 1 portion on a floured work surface until thin and about 10 in. wide. Transfer to a pizza peel or rimless baking sheet dusted generously with semolina. Spread or spoon half of fromage blanc mixture onto dough. Sprinkle with half of dandelion mixture.
Slide pizza onto pizza stone and bake until browned and crisp, about 16 minutes.
Transfer pizza to a cutting board using a wide spatula. Sprinkle with a few curls of pecorino cheese.
Make second pizza with remaining ingredients.