Garlicky Swiss Chard

Heat 2 tablespoons oil and garlic in Dutch oven over medium-low heat, stirring occasionally, until garlic is lightly golden, about 3 minutes. Stir in chard, 1/4 teaspoon salt, and pepper flakes. Increase heat to high and cook, covered, stirring occasionally, until chard is wilted but still bright green, 2 to 4 minutes. Uncover and continue to cook, stirring frequently, until liquid evaporates, 4 to 6 minutes. Add vinegar and remaining 1 teaspoon oil and toss to combine. Season with salt and pepper to taste. Serve.