Bring a large pot of water to a boil. Liberally salt the water and cook linguine to al dente.
Heat olive oil in a large skillet over medium-high heat. Add onions and cook until soft, about 2-3 minutes. Add tomatoes and toss to combine. Cook for 2-3 minutes or until tomatoes are soft and charred. Add basil and cook until flavors are combined, about 3-4 minutes.