Cut each baking potato lengthwise into 6 equal slices. Place potato slices in a large bowl, and drizzle with olive oil. Sprinkle with salt; toss well to coat potato slices. Remove potato slices from bowl. Reserve remaining olive oil and salt in bowl; set aside. Arrange potato slices in a single layer on a baking sheet.
Bake at 400° for 40 minutes or until the potato slices are golden brown on the bottom. Remove potato slices from oven (leave oven at 400°).
Add sage leaves to reserved olive oil and salt in bowl. Gently rub sage leaves along bottom of bowl, coating both sides with olive oil and salt. Working with one potato slice at a time, lift potato slice from baking sheet with a thin spatula. Lay 1 sage leaf on baking sheet, and cover with potato slice, browned side down. Repeat with remaining potato slices and sage leaves.
Bake at 400° for 10 minutes. Remove from heat. Using a thin spatula, carefully turn potato slices over with leaves on top. Bake at 400° for an additional 10 minutes or until bottoms begin to brown. Serve immediately.