Cut the squash lengthwise, scoop out the seeds, and slice into quarter-inch slices.

Pour two tablespoons of the olive oil into a large frying pan and heat over medium heat. Sprinkle the squash with salt and lay it in the pan in one layer (you may need to do it in two batches). Cook the squash until browned on both sides, remove it from the pan, and set aside.

Add the remaining two tablespoons of the olive oil to the pan. Lay the mushrooms in the pan in a single layer, sprinkle with salt and cook until browned on both sides. Add the garlic and cook until fragrant, about 30 seconds. Remove the mushrooms from the pan.

To serve, lay the mushrooms and squash on a plate and sprinkle with fresh parsley and freshly ground black pepper.