Cook the pasta in a large pot according to package directions.

In a large bowl, combine tomatoes, red onions, half of the minced garlic, salt, pepper, 2 tablespoons of olive oil, 1 tablespoon of balsamic vinegar, and 2 tablespoons of basil. Mix well to make the bruschetta mixture. Set aside.

In a large skillet over medium-high heat, add the remaining olive oil. Add the rest of the garlic and oregano, stirring for about a minute until the garlic is soft and fragrant. Slowly add a bit of hot starchy pasta water (about ¼ cup) to the skillet. Add the butter and stir until melted.

Drain the cooked pasta and add it to the skillet. Gently toss to coat the pasta with the garlic sauce. Mix in the lemon juice and mozzarella cheese. Add the tomato bruschetta mixture and toss until the pasta is well coated. Season with salt and pepper to taste. Drizzle with the remaining balsamic vinegar and sprinkle with the remaining basil before serving.