Combine water and cornmeal in a medium saucepan; stir well. Bring to a boil, and cook 1 minute, stirring frequently. Remove from heat; stir in milk and next 7 ingredients (milk through pimento). Set cornmeal mixture aside.
Beat the egg whites at high speed of a mixer until foamy. Add sugar, beating until stiff peaks form. Gently stir one-fourth of egg white mixture into the cornmeal mixture; gently fold in the remaining egg white mixture. Fold in the Roasted Summer Squash.
Spoon mixture into a 1 1/2-quart casserole dish coated with cooking spray. Bake at 375° for 50 minutes or until set.