Coat a large nonstick skillet with cooking spray, and place over medium heat until hot. Add sausage, and cook 10 minutes, turning occasionally.
Remove sausage from skillet; carefully slice each piece in half lengthwise, cutting to, but not through, other side. Open the halves, laying sausage flat. Return sausage to skillet, placing cut sides down; cook 2 minutes or until sausage is done. Remove sausage from skillet; set aside, and keep warm. Add spinach to skillet; cover and cook 2 minutes or until wilted. Remove spinach from skillet; set aside, and keep warm.
Slice each French bread roll in half horizontally. Rub cut sides of bread with garlic halves, and brush with olive oil. Coat skillet with cooking spray, and place skillet over medium-high heat until hot. Arrange bread, cut sides down, in skillet, and cook for 1 minute or until toasted.
Divide spinach between bottom halves of bread, and sprinkle with pepper and salt. Top each sandwich with sausage, and cover with top halves of bread.