Bring a large pot of salted water to a boil over medium-high heat.
Stir in the tortellini and cook for 1 and 1/2 minutes. Don’t overcook the pasta.
Drain the pasta and rinse under cold water until the pasta is cool.
Add the drained tortellini to a large bowl.
Add in pesto, tomatoes, cheese, and onion.
Toss to combine.
Serve immediately or cover and chill until ready to serve.
Notes
Cheese Tortellini: Any brand of fresh cheese tortellini will work. Feel free to use another type (like tricolor) in the recipe.
Pesto: Store bought or homemade basil pesto will work.
Cherry Tomatoes: Flavor bombs cherry tomatoes are my current favorite. You can also use grape tomatoes.
Mozzarella Balls: I use mozzarella pearls. They're mini mozzarella balls. You can use larger mozzarella balls or even marinated mozzarella if you prefer.
Red Onion: Shallots make a good substitute for the red onion. If you find red onion overpowering, simply soak the raw red onion in ice water to take some of the bite out of the onion.
I like to add in a bit of extra pesto after the pasta salad has been in the fridge, so if you're making this ahead of time, you may want to do the same and add a bit of extra pesto before serving.