Fill your largest pot with 6 quarts water and bring to a rolling boil. Salt until it tastes like the sea — this is 80% of your seasoning.

While water heats, prep everything: slice mushrooms 3 mm thick, slice garlic paper-thin (mandoline is fastest), zest both lemons with microplane, juice them, grate Parmesan.

Heat your widest sauté pan (14-inch) over medium-high for 90 seconds. Add the entire 100 g butter. Swirl constantly as it melts, foams, then turns golden → light brown → hazelnut color with tiny brown flecks (about 3–4 minutes total). The second it smells toasty, proceed.

Immediately add all the mushrooms in one layer. Do NOT stir for 3 full minutes — let them drink up the browned butter and turn golden.

Drop pasta into the boiling water now. Set timer for exactly 7 minutes (it will finish in sauce).

After 3 minutes, toss mushrooms, season with ½ tsp salt, and cook another 3–4 minutes until deeply golden and any liquid has evaporated. Push to the edges.

Add paper-thin garlic to the center. Cook 45–60 seconds until pale golden and fragrant. Pour in white wine — it will sizzle dramatically. Scrape up every brown bit and reduce by two-thirds (about 2 minutes).

Remove pan from heat. Add lemon juice and ½ cup pasta water. Swirl to emulsify.

Scoop out 2 full cups pasta water total. Using tongs, transfer pasta directly from water into the sauce (some water clinging is perfect). Add ¾ cup more pasta water, return to medium heat, and toss vigorously 90 seconds. Add Parmesan in 3 batches while tossing — the sauce will turn glossy and clingy. Add more pasta water if needed until it glides.

Remove from heat. Add lemon zest, parsley, tons of black pepper, and one final toss. Let rest in pan 4 minutes (sauce thickens perfectly). Twirl into warmed bowls, shower with extra Parmesan, another crack of pepper, and a few drops of truffle oil if using. Serve immediately with chilled white wine and zero conversation for the first minute.