Bring a large pot of water to a rolling boil. Add salt until the water tastes noticeably seasoned.

Add the whole wheat spaghetti and cook for 2 minutes less than the package direction, stirring occasionally so the noodles don't clump.

While the pasta cooks, pour the olive oil into a wide skillet over medium-low heat. Add the sliced garlic in a single layer.

Cook the garlic gently for 3 to 4 minutes, stirring once, until the edges turn pale gold. Watch it closely - it goes from golden to burnt quickly.

Add the chili flakes to the oil and stir for 30 seconds until fragrant. Remove the pan from the heat immediately.

Scoop out 200 ml of pasta water and set it aside, then drain the spaghetti.

Return the skillet to medium heat. Add 100 ml of the pasta water to the garlic oil and stir - it will sizzle and start to emulsify.

Add the drained spaghetti to the pan. Toss well using tongs, adding more pasta water a splash at a time until the sauce loosely coats every strand and there is no oil pooling at the bottom.

Remove from the heat. Add the chopped parsley and toss once more until evenly distributed and the parsley stays bright green.

Divide into warm bowls. Top with grated Pecorino Romano and a pinch of extra chili flakes if you like.