Preheat oven to 375°F. Arrange bacon on a slotted pan or a baking rack set into a baking sheet and bake to crisp, about 15 minutes or so.
In a small skillet, sauté the fennel, apples and onion over medium heat in a drizzle of EVOO. Cook to tender-crisp, 7-8 minutes, then add sauerkraut and heat through.