Place a large non-stick skillet over medium heat and add 1 tbsp of olive oil, Add the sliced mushrooms and onions to the pan. After 2-3 minutes, add 1 tbsp of balsamic vinegar. Stir. Let it cook down for another 2-3 minutes and then add the second tbsp of Balsamic vinegar. Sauté for an additional 2-3 minutes, set aside.
Place all of the Summery Sun-dried Tomato-Basil Pesto ingredients into a food processor or blender. Blend until everything has fully mixed and to your desired consistency. You may need to stop and scrape down the edge as mix comes together.
Cook the VG Gourmet Lentil-Walnut Burgers, following the packaging instructions.
Enjoy! Store leftover pesto in a tightly glass-sealed container for up to 2 weeks.