Heat the oil in a large skillet over high heat. Add the lamb cubes and sear on all side. Transfer lamb to a plate and set aside. Lower heat to medium low and add onion, cooking until soft. Deglaze with white wine. Add lamb back to skillet along with rosemary, chicken stock, and salt and pepper. Let cook until lamb is cooked through. Drain skillet of excess liquid and reserve.
In a bowl, mix together the eggs, pecorino, and parsley. Pour mixture into the skillet and cook, stirring, until the egg is firm.
Remove to a plate, garnish with parsley leaves, and drizzle with reserved cooking liquid.
