Bring a large pot of salted water to a rolling boil. Add the spaghetti and cook according to package directions until al dente (about 9-11 minutes). Reserve about 1 cup of pasta water before draining.

Thinly slice the garlic, chop the parsley, and clean the mushrooms. Pat them dry with a towel.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the button and oyster mushrooms in a single layer and cook for 5-7 minutes until golden brown and crispy on the edges; remove from the skillet.

In the same skillet, add the remaining olive oil and garlic. Cook until fragrant and the garlic is just golden (about 2-3 minutes).

Sprinkle in the chili flakes and stir for 30 seconds. Pour in the reserved pasta water and incorporate the sautéed mushrooms back into the dish. Let it simmer for 2-3 minutes.

Add the drained spaghetti into the skillet, tossing to coat in the garlic oil. Add fresh parsley, salt to taste, and mix until warmed through.

Plate and finish with grated parmesan and lemon zest. Serve immediately.