Preheat the oven to 425°F and bring 3 cups of water to a rolling boil in a medium-sized pot.
Once the water is boiling, add the orzo and cook al dente, about 8-10 minutes. Strain the orzo and add it to a large bowl. Add the pesto right away and stir to coat, so the orzo doesn't stick together.
1 cup orzo, ⅓ cup pesto
Meanwhile, rinse and slice the grape tomatoes in half lengthwise.
Add the prepped tomatoes to a baking sheet and add the olive oil, salt, and pepper. Toss to evenly coat.
Roast the tomatoes for 10-15 minutes until the skin starts to wrinkle.
Add the roasted cherry tomatoes and mozzarella pearls to the pesto-coated orzo and stir to combine. Serve hot or cold!
Notes
Watch your tomatoes closely—burnt tomatoes can taste really bitter. If you do burn your tomatoes, consider tossing them in a little bit of honey or maple syrup to balance out that bitterness.