Sweet and Spicy Spinach

In a large skillet over medium heat, add the chopped bacon. Cook until crispy, remove bacon with a slotted spoon and drain on a paper towel. Add chopped red onion to the pan and cook until translucent, scraping the bottom of the pan. Add the drained pineapple, garlic, and pepper flakes, stir and cook until the pineapple is caramelized. Add the spinach to the pan in batches; add 2 tablespoons of the reserved pineapple juice, stirring spinach until it wilts down. Add more juice if it seems too dry. Season with salt and pepper, to taste. Top with crumbled bacon.