Cook the spaghetti in well-salted boiling water until just short of al dente. Reserve a mug of the water before draining.

While it cooks, melt the butter with a little olive oil in a large frying pan over low heat — low, so the garlic sweetens instead of browning.

Add thinly sliced garlic and cook gently for 2 minutes until soft and pale gold. If it browns, start again; burnt garlic is bitter and will define the dish.

Add the spinach a handful at a time, stirring until each handful collapses before adding the next.

Add the drained pasta and a good splash of pasta water. Toss over medium heat for a minute until the sauce clings.

Off the heat, stir through the grated cheese and plenty of black pepper. Taste and add salt if needed.