In a large sauté pan, sauté the garlic over medium-high heat in the olive oil until golden-brown but not burnt, roughly 1 to 2 minutes.
Remove the garlic with a slotted spoon and set aside in small bowl.
Add the tomato paste and cook until warmed. Add the stock and vinegar and bring to a low boil.
Add the garlic and chard and reduce to a simmer. Cook until the chard is tender, about 20 minutes. Season with salt (I love salt so feel free to add less if you aren't as in love with sodium as I am!) and red chile flakes, if using. Serve warm over a grain like quinoa or farro so all the juices get soaked up, with some chicken on the side if you like!