Bring a large pot of water to boil and add 1 tablespoon of salt per 2 litres of water. Add the agretti and boil for 7 minutes.
White the agretti are boiling, warm a frying pan over medium heat and add 3 tablespoons of the olive oil. When the olive oil is hot then add the anchovies.
Once the anchovies have melted, 1 to 2 minutes, add the garlic and cook until the garlic slightly begins to colour, about 1 minute.
Drain the agretti and add to the anchovy/garlic mixture, stirring. If your garlic is ready before your agretti, you can add a bit of the water the agretti are cooking in to stop the garlic from burning.
Taste the agretti and see if you need more salt and add to taste. Drizzle the final tablespoon of olive oil over the top and serve.