Wash beet greens thoroughly. They tend to be muddy, so wash twice. Dry in a salad spinner or towels.
Separate greens from the stalks. Remove woody parts and cut stalks into ½ inch pieces. Roughly chop leaves.
In a large skillet, sauté pancetta or bacon for 2 minutes. Add in onion and garlic and sauté for 1 minute. Add stalks and sauté for 5 minutes.
Add water, put lid on, and cook for 5 minutes, or until stalks start to soften. Add greens and cook 5-10 minutes, until greens and stalks are tender and cooked to preferred tenderness.
Remove from heat and stir in 2 Tablespoons vinegar. Add pepper and salt to taste. Drain and transfer greens to serving dish (without liquid).
Notes
*Stalks may be omitted. Cook times remain the same.