Gather all ingredients.

Bring a large pot of lightly salted water to a boil. Place tortellini in the pot and cook until al dente, 7 to 8 minutes. Drain and cool.

Mix cooked tortellini, bell pepper, broccoli, carrots, olives, and garlic in a large bowl.

Whisk mayonnaise, pesto, milk, Parmesan cheese, oil, and vinegar together in a separate bowl. Pour over tortellini and vegetables and gently toss to coat.

For best flavor results, cover and place in the refrigerator until chilled. Serve over spinach leaves.