The nuttiness of walnut-parsley pesto brings out the natural sweetness of grilled summer squash in this dish that pairs well with pork chops, mussels, or flank steak.
Heat a grill or grill pan to medium-high. In a food processor, pulse parsley, walnuts, garlic, Parmesan, lemon zest, and lemon juice until combined, about 10 seconds. With machine running, add olive oil in a slow, steady stream and process until a paste forms. Season pesto with salt and pepper and transfer to a small bowl.
Clean and lightly oil hot grill. Season squash with salt and pepper. Working in batches, grill squash, turning occasionally, until lightly charred and tender, about 10 minutes. Transfer to a platter and serve with pesto.
These squash are good with pork chops, mussels, or flank steak.