Sauteed Kale With Red Wine Vinegar | Heart Healthy Side

Ingredients

• 2 1/2 lbs kale, tough stems, center ribs discarded and cut into 1-inch strips
• 2 Tbsp olive oil
• 1 medium red onion, halved lengthwise and thinly sliced crosswise
• 3 garlic cloves, minced
• 1/2 tsp crushed red pepper flakes
• 2 Tbsp red wine vinegar, or to taste
• 1/4 tsp salt