Pizza Quattro Stagioni is a limited main dish. It was only available from March 15 to April 12, 2011. It begins at level 0 and unlocks only after Pizza Marinara is mastered. To achieve level 10 in this dish, you need 10 mushroom, 10 ham, 10 pepperoni, and 10 sweetcorn.
Mastering Pizza Quattro Stagioni earns you the Lil' Old Stove (20% total speed boost for your Pizzeria). Mastering Pizza Quattro Stagioni also unlocks Pizza Prosciutto e Funghi.