6 slices bacon, cut into 1/4-inch-wide pieces
1 medium red onion, halved and sliced pole to pole into 1/4-inch slices
5 medium garlic cloves, minced or pressed through a garlic press (about 5 teaspoons)
1/8 teaspoon red pepper flakes
2 pounds kale or collard greens, ribs removed, leaves chopped into 3-inch pieces and rinsed
1 cup low-sodium chicken broth
1 cup water
3–4 teaspoons cider vinegar
Ground black pepper
Cut 6 slices bacon into ¼-inch-wide pieces and cook over medium heat in a pot until crisp, 8 to 10 minutes. Using slotted spoon, transfer bacon to paper towel-lined plate and discard all but 2 tablespoons fat.
Heat the 2 tablespoons of fat over medium heat until shimmering. Add onion and cook, stirring frequently, until softened and beginning to brown. Add garlic and pepper flakes; cook until garlic is fragrant, about 1 minute.
Add half of greens and stir until beginning to wilt, about 1 minute.
Add remaining greens, broth, water, and ¼ teaspoon salt; quickly cover pot and reduce heat to medium-low.
Cook, stirring occasionally, until greens are tender, 20-25 minutes for kale and 35 to 45 minutes for collards.
Remove lid and increase heat to medium-high. Cook, stirring occasionally, until most of liquid has evaporated (bottom of pot will be almost dry and greens will begin to sizzle), 8 to 12 minutes.
Remove pot from heat; stir in 3-4 teaspoons apple cider vinegar and remaining tablespoon olive oil. Season with salt, pepper, and remaining teaspoon cider vinegar.
Stir reserved bacon into greens and serve.
Check out the video below. Recipe starts at 10:53.