2 tablespoons olive oil
1 medium onion, chopped
4 garlic cloves, minced
2 pounds zucchini, or a combination of green and yellow summer squash, diced
2 pounds tomatoes, peeled, seeded and chopped, or 1 (28-ounce) can, drained and chopped (see note below)
1/4 teaspoon sugar
Salt to taste (a generous amount, at least 1 teaspoon)
Lots of freshly ground black pepper
Note: When you seed the tomatoes, set a strainer over a bowl. Squeeze the seeds into the strainer, then press the pulp and juice through the strainer into the bowl. Discard the seeds and use the juice as described below.
Heat the oil in a large, heavy, nonstick skillet over medium heat, then add the onion. Stir often, until just about tender about 5 minutes.
Add the garlic and cook, stirring, for another minute or two until fragrant.
Stir in the squash and 1/2 teaspoon salt, and toss together for five minutes, until the squash is coated with oil and beginning to soften.
Add the tomatoes and sugar, then salt to taste (3/4 to 1 teaspoon) and turn the heat to medium-high. Stir often for five to 10 minutes, until the tomatoes have slightly cooked down.
Add the juice from the tomatoes plus 1/4 cup water, stir together, and turn the heat back down to medium-low. Cook uncovered for 30 to 35 minutes, until the vegetables are soft and easy to mash. Stir often, and add water as necessary, every 10 minutes or so, until the mixture cooks down and begins to stick to the pan. From time to time, press on the squash with the back of your spoon so that it breaks down. Taste, adjust the salt, and add lots of pepper.
Using the back of your spoon, make six wells in the vegetable mixture and break an egg into each well. Sprinkle with salt and pepper. Cover the pan, and cook until the eggs have set, about six to eight minutes (the whites should be set, but the yolks should still be runny).
Serve, using a spatula to dish out portions of pisto topped with an egg.
Advance preparation: The pisto will be delicious for three or four days, but until you reheat it, don’t cook the eggs. To reheat the pisto, preheat the oven to 400 degrees. Transfer the cooked pisto to a lightly oiled baking dish. Make six depressions in the top, and break an egg into each one. Salt and pepper lightly, and bake in the oven six to eight minutes or until the eggs set.