Wrap the head of garlic in aluminum foil and roast it in the oven for about 40 minutes, until the garlic is tender. Remove from the oven, let it cool, cut in half, and squeeze out the garlic paste. Set aside.

In a pot, brown the butifarra sausage cut into bite-sized pieces along with the finely chopped green onion.

Meanwhile, cook the pasta according to the package instructions.

When the green onion is soft, add the garlic paste and tahini. Stir and season with salt and pepper to taste.

Add the pasta and stir. If needed, add a little pasta cooking water to bind the sauce. Add the lemon juice and cheese. Let the sauce thicken.