Tangy Kale With Garlic And Onions

5 Tbsp olive oil, divided
2 medium red onions, sliced in circles, then in half
3 garlic cloves, minced
3 to 4 lbs fresh kale, stems removed, cut in strips, washed and dried well
1/2 tsp salt
1/2 tsp ground black pepper
3 to 4 Tbsp balsamic vinegar

Heat 2 tablespoons of the olive oil in a large heavy skillet over medium-high heat.
Add the onion and cook until soft and just beginning to brown a little; remove from skillet and set aside.
Reduce the heat under the skillet to medium-low, add the garlic, cooking just until fragrant, about 1 to 2 minutes; remove from skillet and save with onion.
Add the remaining oil and turn the heat back up to medium-high, then add the kale and cook, stirring frequently, until the kale just wilts.
Add back in the skillet the cooked onion and garlic, then the salt and pepper.
Reduce the heat again to medium-low and continue cooking, tossing the mixture occasionally, until the kale is tender, about 5 minutes.
Sprinkle the balsamic vinegar into the mixture just before serving, toss and serve hot as a side dish for grilled, roasted, or barbecued meat, poultry, or fish.
Makes 4 servings.