SERVING SIZE: 3 cups
10 ripe plum tomatoes (or one 28-ounce can of peeled whole plum tomatoes)
1 cups Spanish extra-virgin olive oil
4 small Spanish onions, peeled and finely chopped (about 4 cups)
1 teaspoon sugar
1 teaspoon salt
1 teaspoon pimentn (Spanish sweet paprika, although I only had - gasp - Hungarian)
1 bay leaf
Cut the tomatoes in half. Place a grater over a large mixing bowl. Rub the open face of the tomatoes over the grater until all the flesh is grated. Discard the skin. (The tomatoes I found looked so saggy that I went with canned. I drained and finely chopped the amount I found in one 28-ounce can.)
Heat the oil in a medium saucepan over a medium-low flame. Add the onions, the sugar and the salt. Cook, stirring occasionally with a wooden spoon, until the onions become soft and tender and turn a light brown color, about 45 minutes. You want the onions to caramelize. If they get too dark (as mine almost did), add tablespoon of water to keep them from burning while they cook.
Add the reserved tomato puree, the pimentn, and the bay leaf. Cook for another 20 minutes over medium heat. You'll know your sofrito is ready when the tomato has broken down and deepened in color, and the oil has separated from the sauce.
Note: Once you have sofrito made, paella is seriously easy to whip up. And if you follow the recipe below, you'll have leftover sofrito. Freeze it in an ice cube tray then store the cubes in a freezer bag so they won't take on any bad flavors. When you're ready for your next taste of Spain, the chef says to thaw it slowly in the fridge (so it doesn't get watery) and use about two cubes' worth per paella recipe.