Remove green peas from freezer and allow to thaw slightly at room temperature, about 30 min. In a food processor, blend peas, scallions, shallots, parsley, and rosemary until coarse in texture and combined. Transfer to a medium bowl and add spices and flour and fold together until completely mixed. Seal the bowl using plastic wrap and refrigerate for 30 min. to allow flavors to meld. This mixture can be made up to 48 hours before cooking.
Form falafels by rolling tightly into about 12 to 14 ping pong-sized balls. Heat vegetable oil in a large cast iron skillet over medium-high heat. When oil is hot, carefully add half of the falafels, flattening each slightly with the back of a serving spoon. Cook for 2 to 3 min. until the bottom of the bright green falafel has turned a dark brown. Using a spatula and a serving spoon, carefully turn each falafel over and cook for another 2 to 3 min. or until dark brown. Transfer to a paper towel lined cooling rack on a cookie sheet to drain. Repeat with remaining falafel.