Heat the oil in your casserole pan and add the diced white onion, sauting for 5 - 8 minutes.
Then add the minced garlic and cook for another minute.
Add the red pesto and the tomato paste to the pan along with your seasoning, and stir everything together. Let the pastes cook down and release their flavors, cooking on low heat for 2-3 minutes.
Pour in the cream, stir, and then add the gnocchi. Stir the gnocchi to fully coat it in the sauce, and layer over the mozzarella slices.
Grill the dish for about 10 minutes until the cheese is melted and the tops of the gnocchi have turned golden and crispy.
Scatter over your fresh basil and serve!
