Heat the oil in a large skillet over medium heat. Add the garlic and cook, stirring, until golden, 2 to 3 minutes. Add the chard, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Cook, tossing occasionally, until the chard is tender, 4 to 5 minutes.
Meanwhile, in a medium saucepan, bring 4 cups of water to a boil. Add 1 tablespoon salt. Slowly whisk in the polenta. Cook, whisking constantly, until the polenta thickens, 3 to 4 minutes.
Divide the polenta among bowls and top with the chard and blue cheese.
Tip: Make a double batch of polenta and reserve half in an oiled loaf pan for a quick side dish later in the week. Simply slice the polenta and crisp it by popping it in the broiler or pan-frying it.