I know it doesn’t sound very glamorous, but slowly cooked sliced onions are one of my favorite toppings for a focaccia. For a delicious variation, halve, seed, and thinly slice 450g red peppers and cook them along with the onions.
Start cooking the onions before step 1 of the master dough recipe, left. Combine the oil and onions in a wide sauté pan that has a lid. Place on a medium heat and when the oil starts to sizzle, reduce to low, cover the pan, and cook, stirring occasionally, until the onions are soft and translucent, about 30 minutes. Uncover the pan, season with a little salt and increase