Bring a large pot of salted water to a boil and cook the tortellini according to the package instructions. Drain the pasta and mix with 1-2 tablespoons of olive oil to keep the pasta from sticking. Set aside.
Slice the zucchini into about 1/4 inch slices and toss with salt, pepper, garlic powder, and 2 tablespoons of olive oil. Place the zucchini slices on the parchment paper-lined air fryer tray, or baking sheet, if you are using the oven.
Preheat the air fryer to 400 degrees then air fry the zucchini slices for 15 minutes, or until they are browning but not burning. You will likely need to do these in two batches. If you are using the oven, preheat to 450 degrees and bake for approximately 5 minutes, then broil for 1-2 minutes until the slices are browning but not burning.
Meanwhile, add the tortellini to a large bowl and mix in the pesto. Add the zucchini, walnuts, parsley and Pecorino Romano, and gently mix to disperse throughout the pasta. Top with additional parsley, walnuts and Pecorino Romano. Serve at room temperature.
