In 4 tablespoons hot butter in heavy 3 quart saucepan saute onion and parsley 5 minutes. Add 2 cups water; bring to boiling. Reduce heat and simmer, covered, without stirring 14 minutes or until liquid is all absorbed. Meanwhile, cook peas as package label directs; drain well. Stir peas, salt and remaining butter into rice. Turn on serving dish. Sprinkle top with grated Parmesan cheese. Makes 6 to 8 servings. Note: You may substitute 1 1/2 cups fresh shelled peas for frozen peas. Cook in boiling salt water 10 to 15 minutes or until just tender. Drain well and add to rice.