Preparation Gently mix first 6 ingredients in large bowl. Season tuna-tomato mixture to taste with salt and pepper. Let stand 1 hour at room temperature. Cook spaghetti in large pot of boiling salted water until just tender but still firm to bite, stirring occasionally. Drain; return to pot. Add tuna-tomato mixture and basil. Toss to combine. Season with salt and pepper. Transfer to bowl and serve.
Preparation Gently mix first 6 ingredients in large bowl. Season tuna-tomato mixture to taste with salt and pepper. Let stand 1 hour at room temperature. Cook spaghetti in large pot of boiling salted water until just tender but still firm to bite, stirring occasionally. Drain; return to pot. Add tuna-tomato mixture and basil. Toss to combine. Season with salt and pepper. Transfer to bowl and serve.