In a small mixing bowl, combine the ricotta and sour cream until smooth. If you feel like the dip is too thick, you can add a little more sour cream until your desired consistency is reached.

Stir in the pesto until well combined. (Or stir the pesto briefly so it's kind of swirled on the top.)

In a small bowl, toss together the tomatoes, balsamic vinegar, and oil. Allow to sit for 1-2 minutes to the tomatoes can marinate a little.

Carefully spoon the tomatoes into the center of the dip. You can leave the excess dressing in the bowl, or drizzle it on the dip as well.

Chill until ready to serve.