This is a very simple concoction to make and adds a wonderfully rich and aromatic base flavor for a pizza, a savory tart, crostoni, Spanish omelet…
Makes 1 1/4 cups (enough for 3 10 inch pizzas)
- 5 tablespoons extra virgin olive oil
- 2 tablespoons unsalted butter
- 3 medium onions, peeled and diced
- 1 head of garlic, cloves peeled and thinly sliced lengthwise
- 1/2 teaspoon salt + more to taste
- several twists of fresh ground white pepper
- 1 tablespoon lemon juice (Optional)
- 1 teaspoon lemon zest (optional)
- 1/2 teaspoon lemon thyme (optional)
Heat the olive oil and butter together in a saucepan until the butter is melted. Add the onions and garlic and stir to combine. Add the salt and pepper and stir in. Turn the heat down to as low as you can get it and cover with a lid. Stir now and again and cook, without browning, for about 45 minutes. Add the optional ingredients (if using) and stir them into the puree. Set aside to cool to room temperature.
Place the onion garlic mixture in a food processor or blender and process into a smooth puree. Taste for seasoning and add salt if needed.
Transfer the puree to a bowl, cover with cling film and refrigerate for up to five days. Return the puree to room temperature before using.