Sauteed Kale

Directions

1. 1
   Cook kale in a 6-quart pot of boiling salted water , uncovered, stirring occasionally, until just tender, about 10 minutes, then drain in a colander.
2. 2
   Heat oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then saute onion, stirring occasionally, until softened, 6 to 8 minutes.
3. 3
   Add garlic and red pepper flakes and saute, stirring, until garlic is fragrant, about 1 minute.
4. 4
   Reduce heat to moderate, then add kale and cook, stirring occasionally, until heated through.
5. 5
   Remove from heat and stir in vinegar and salt.