Oven Roasted Zucchini
Also known as “Thomas Keller’s zucchini”, this unbelievably delicious squash is plump, tender, and perfectly caramelized. One simple technique transforms a crisp vegetable into a pillowy, creamy one – with just three ingredients. Rich in both sweet and savory nuances, this scored, seared, and roasted zucchini needs nothing else. The addition of my vibrant, tomato-based vierge sauce simply escalates the dish to another incredible level.
This recipe was written for the Arizona Republic.
What’s unique about the Thomas Keller method for cooking zucchini? Thomas Keller employs a two-step process for cooking the squash – pan-searing and roasting. Pan-searing in hot oil produces a golden brown, caramelized layer, and roasting in a very hot oven softens the flesh and skin. The result is squash with a sweet/savory surface, and custard-like core. And you need just three ingredients (zucchini, salt, oil) to make the magic happen.
The vierge sauce is optional, but highly recommended! As I mentioned, this zucchini is flavorful enough to be served alone, without the addition of a sauce. But since the recipe is quite simple, you’re afforded the time to craft something to go along with it. I followed Thomas Keller’s lead by creating a vierge sauce (virgin sauce), the French version of salsa. Thomas Keller’s recipe marries tomatoes with champagne vinegar, shallots, olive oil, and fresh herbs. It’s light and lovely but wait until you try my version with tomatoes, Greek olives, lemon, garlic, and green onions; you’ll want to spoon it over everything.
Before we get started on this nutritious, super simple dish, here are a few tips to guarantee success.
Choose medium zucchini. This recipe works best with medium squash, not the smaller zucchini. Three medium zucchini should weigh about 1 1/4 pounds (use the scale in the produce department of your grocery store). You can also use yellow squash, or a combination of zucchini and yellow squash. I used a combination.
Salt your zucchini before cooking. Zucchini is 94 percent water, which is why it gets mushy when cooked for too long. The first step in this recipe involves salting the flesh of the zucchini and allowing the squash to stand for 15 minutes. The salt draws the moisture from the flesh which helps ensure that the vegetable stays firm during roasting. This moisture (and excess salt) is patted off with a paper towel before cooking. Added benefit: the salt works its way into the scores of the flesh and seasons the zucchini all the way to the center.
Use oil with a high smoke point and neutral flavor. There are two cooking methods in this recipe – pan-searing and roasting – which both require very high heat. Choose an oil with a high smoke point and neutral flavor, such as canola, avocado, or grapeseed. When pan-searing the zucchini, make sure you have enough oil to cover the surface of the pan by about 1/8-inch.
Make the vierge sauce while the zucchini is salted.This gives the ingredients a chance to mingle and evolve before serving. You can also prepare the vierge sauce one day in advance. Store the sauce in the refrigerator and bring to room temperature before serving.
Check the oven often. Since we’re cooking the zucchini at a very high temperature, and it’s already pan-seared, check for tenderness after 15 minutes. The size of your zucchini, the pan you’re using, and how caramelized the vegetable is, will all affect cooking time. When finished cooking, the zucchini will be completely tender. My zucchini was perfectly soft at 15 minutes.
Consider other sauces! If vierge sauce isn’t in the cards for you, other great toppings include minced roasted red peppers with feta, marinara sauce with parmesan cheese, store-bought salsa, and pesto. Remember, you can certainly serve this amazing zucchini without anything at all.
Oven Roasted Zucchini
Ingredients
For the Zucchini
- 3 medium zucchini, or a combination of zucchini and yellow squash, about 1 1/4 pounds total
- Salt
- 2-3 tablespoons canola oil, or neutral oil with a high smoke point, such as avocado or grapeseed, or more if needed to coat the pan
For the Vierge Sauce
- 2 medium vine-ripened tomatoes
- 2 tablespoons extra-virgin olive oil
- 2 tablespoons diced Greek olives, or Spanish olives
- 1 green onion, chopped
- 2 teaspoons fresh lemon juice
- 1/2 teaspoon grated fresh garlic
- Salt and freshly ground black pepper to taste
Instructions
- Preheat oven to 450 degrees.
- Halve the zucchini lengthwise and score the flesh in a crosshatch pattern, about 1/8-inch deep.
- Sprinkle the scored side of the zucchini with salt (Chef Keller recommends sprinkling the salt like “rain” or “snow” so it covers the flesh evenly). Let stand for 15 minutes to allow the salt to pull moisture from the flesh; this technique ensures that the zucchini stays firm during roasting.
- Meanwhile, make the vierge sauce: Halve the tomatoes crosswise and use a small spoon to scoop out (and discard) the watery insides and seeds. Finely dice the tomatoes and transfer them to a medium bowl. Add the olive oil, olives, green onion, lemon juice, and garlic and toss to combine. Season with salt and black pepper.
- Pat the zucchini dry and remove excess salt.
- Heat the canola oil in a large, ovenproof skillet over medium-high heat (the oil should cover the surface of the pan by about 1/8-inch). When the oil is shimmering (but not yet smoking), add the zucchini, flesh side down. Sear until nicely browned and caramelized, but not burned, checking frequently. This should take about 5 minutes.
- Transfer the pan to a lower oven rack and cook for 15 to 20 minutes, until the zucchini are very soft (timing will depend on the size of the zucchini and how deeply they were caramelized; check after 15 minutes – if the zucchini are soft to the touch, they’re ready).
- Transfer the zucchini to serving platter and, if necessary and desired, blot with paper towels to remove excess oil.
- Top the zucchini with some of the vierge sauce and serve with extra sauce on the side.