In a large, deep skillet, heat the olive oil. Add the garlic and cook over moderate heat until lightly golden around the edges, about 3 minutes. Add the crushed red pepper and cook for 30 seconds. Add the onion and cook until translucent, about 4 minutes. Add the Swiss chard stems and leaves and the chickpeas and cook over moderately high heat, stirring frequently, until the greens are wilted, about 10 minutes. Add the chicken broth and cook until the stems are tender and the pan is dry, about 3 minutes. Season with salt and pepper. Transfer to plates and serve.