In a large skillet, saute the spinach, mushrooms, onions and pecans in oil until mushrooms are tender.
Set aside and keep warm.Sprinkle chicken with seasoning.
Using long-handled tongs, moisten a paper towel with cooking oil and lightly coat the grill rack.Grill chicken, covered, over medium heat or broil 4 in.
from the heat for 4-5 minutes on each side or until a meat thermometer reads 170°.Top with cheese.
Cover and grill 2-3 minutes longer or until cheese is melted.
To serve, top each chicken breast with reserved spinach mixture.