In a large pot, bring water to a boil. Add a pinch of salt, and cook the spaghetti according to package instructions until al dente. Reserve about 1 cup of pasta water before draining.

In a large skillet, heat the olive oil over medium heat. Add minced garlic, sautéing until fragrant but not browned—about 1-2 minutes.

Toss the sliced mushrooms into the skillet with the sautéed garlic. Stir occasionally, cooking until the mushrooms are tender and golden brown—about 5-7 minutes.

Add the drained spaghetti to the skillet with the mushrooms. Toss everything together, gradually adding reserved pasta water until the desired consistency is reached.

Stir in grated parmesan, salt, and pepper to taste. Remove from heat, garnish with fresh parsley, and serve immediately.