Prick potatoes before cooking.
Place in oven Microwave on high for 10 to 11 minutes or until potatoes are fork-tender; set aside.
Combine peas and water in 2-quart casserole Cover with glass lid or plastic wrap.
Microwave on high for 6 minutes or until peas are tender-crisp; set aside.
Combine butter and onion in 4-cup glass measure.
Microwave on medium for about 1 minute or until melted.
Blend in flour, salt, dill and pepper.
Stir in milk.
Microwave on high for 4 to 5 minutes or until mixture thickens.
Peel potatoes and add to peas in casserole.
Pour hot cream sauce over vegetables; stir gently to thoroughly coat vegetables, high for 2 to 3 minutes or until piping hot.
Let stand 3 minutes before serving.