Cook the orzo according to package directions until al dente. Drain and set aside in a large bowl.

Sauté the tomatoes: In a skillet over medium heat, warm the olive oil. Add the halved cherry tomatoes and garlic. Cook for 4–5 minutes until the tomatoes begin to soften and burst slightly. Add the balsamic vinegar and a generous pinch of salt, stirring to coat. Cook 1–2 more minutes, then remove from heat.

Toss it all together: While the orzo is still warm, stir in the pesto so it melts into the pasta. Add the cooked tomatoes (with any juices from the pan), mozzarella balls, and a big squeeze of lemon juice.

Taste and adjust with more salt, lemon, or pesto if needed. Serve warm or chilled.