1Heat oven to 425ºF. Spray large cookie sheet with cooking spray.
2Heat water and butter to boiling in 3-quart saucepan over medium heat. Add flour, salt, rosemary and pepper all at once, stirring constantly 30 to 60 seconds or until mixture forms ball; remove from heat.
3Add eggs, 1 at a time, beating with electric mixer on medium speed until mixture is well blended. Drop dough by heaping teaspoonfuls about 2 inches apart onto cookie sheet. Bake 15 to 20 minutes or until golden brown. Cool 5 minutes.
4Gently press center of each puff with tip of spoon to make slight indentation. Sprinkle with cheese and nuts. Bake 2 to 4 minutes or until cheese is melted. Serve warm.