Horizontally split tenderloins to make four 1/2-inch-thick steaks. Rub turkey with sage; sprinkle with salt and pepper. In extra-large skillet cook steaks in 1 tablespoon of the butter over medium-high heat 14 to 16 minutes or until no longer pink (170 degrees F), turning once. (Reduce heat to medium if turkey browns too quickly.) Remove from skillet. Add spinach to skillet. Cook and stir until just wilted.
Meanwhile, in small skillet cook pear slices in remaining 1 tablespoon butter over medium to medium-high heat, stirring occasionally for 5 minutes or until tender and lightly browned.
Serve steaks with spinach and pears. Top with blue cheese.