Cook potatoes in boiling water 15 minutes or until tender; drain.
Heat oil in a nonstick skillet over medium-high heat. Add onion, bacon, pepper, and garlic; sauté 5 minutes or until tender.
Cut potatoes in half; carefully scoop out pulp, leaving a 1/4-inch shell. Mash potato pulp with a fork; stir in cheese and sage. Add to onion mixture, stirring well. Spoon about 1 tablespoon potato mixture into each shell. Arrange stuffed potatoes on a baking sheet, and broil 3 to 4 inches from heat 3 minutes or until lightly browned. Serve warm.