Heat the oil in a large skillet over medium heat.
Add diced tomato, half of the basil, the garlic and salt and pepper. Cook until thickened, stirring often, about 20 minutes. Add frozen peas then reduce heat to low.
Meanwhile, cook pasta according to package directions; drain and place in a large bowl; toss with butter, remaining basil and the hot tomato mixture.
Sprinkle with freshly grated Parmesan cheese.