Preheat oven to 425°F. Line a rimmed baking sheet with nonstick foil (or spray foil with cooking spray).
Toss sliced tomatoes and garlic with 1 tablespoon olive oil. Pour in a single layer onto prepared baking sheet. Cook for 25 to 30 minutes, or until tomatoes soften and garlic browns (watch carefully so it doesn't burn).
Meanwhile cook tortellini according to package directions. Drain and put into serving bowl.
In a small bowl, mix remaining olive oil and balsamic vinegar until combined.
Pour roasted tomatoes and garlic over tortellini, toss gently to combine.
Pour olive oil/balsamic vinegar mixture over tomatoes and toss to coat. Top with fresh Parmesan cheese and/or crushed red pepper, as desired.
Recipe by Alida's Kitchen at https://www.alidaskitchen.com/2014/03/22/balsamic-tomato-tortellini/