Melt butter in a large nonstick skillet over medium-high heat; add asparagus, leeks, and water. Bring to a boil; cover, reduce heat, and simmer for 10 minutes or until tender, stirring occasionally. Stir in parsley, tarragon, lemon rind, salt, and 1/8 teaspoon pepper.
Arrange half of bread slices in a single layer in a 13 x 9-inch baking dish coated with cooking spray. Top bread slices with half of asparagus mixture, and sprinkle with 1/2 cup cheese. Repeat procedure with the remaining bread, asparagus mixture, and 1/2 cup cheese.
Combine 1/8 teaspoon pepper, milk, eggs, and egg white, and stir with a whisk until well-blended. Pour the milk mixture over strata. Cover strata, and chill for 8 hours or overnight.
Preheat oven to 400°.
Uncover strata; sprinkle with breadcrumbs. Bake at 400° for 40 minutes or until set.