Cook the Bacon: In a large skillet over medium heat, cook bacon strips until crispy. Remove from the skillet, drain on paper towels, and crumble into small pieces.
Sauté the Onion and Garlic: In the same skillet, leaving the bacon drippings, add the chopped onion and sauté for 3–4 minutes until softened. Add minced garlic and cook for 30 seconds until fragrant.
Cook the Spinach: Add fresh spinach in batches, sautéing and stirring occasionally until wilted, about 3–5 minutes. Season with salt and pepper to taste.
Combine with Bacon: Stir in the crumbled bacon and cook for another 1–2 minutes to allow the flavors to meld.
Serve: Serve immediately as a savory side dish.
