Cut each zucchini in half lengthwise. Make shallow cuts in a crosshatch pattern on the flesh side. Sprinkle 1 teaspoon of kosher salt over the flesh and let it rest for 15 minutes. The salt will draw water out. The crosshatch pattern helps the salt penetrate the zucchini.
After 15 minutes, the zucchini will have visible water droplets on its surface. Pat it dry using paper towels.
Preheat the oven to 450°F.
Heat the ghee over medium-high heat in a large, 12-inch, oven-safe skillet. I use a cast-iron skillet. Place the zucchini in the skillet in a single layer, flesh side down.
Cook the zucchini for about 5 minutes, until the bottom is browned. If the pan becomes too hot (as is sometimes the case with a cast-iron skillet or if you use an electric stove), reduce the heat to medium.
Turn the heat off. Flip the zucchini and sprinkle it with black pepper, garlic powder, and dried thyme.
Transfer the skillet to the preheated oven. Roast the zucchini for about 15-20 minutes, until tender.
Serve immediately.
Video
Notes
Scoring the zucchini flesh and salting it is an important step. You want to eliminate extra liquid to help the zucchini caramelize and prevent sogginess.
Even though we pat the zucchini dry after salting it, enough salt gets inside thanks to the scoring that there's no need for additional salt.
Smaller zucchinis will need about 15 minutes in the oven. Larger ones will need about 20 minutes. Since zucchinis and ovens vary, you'll need to check and ensure that the zucchini is cooked through, tender, and browned.
You can keep the leftovers in the fridge, in an airtight container, for up to four days. They are excellent when served cold, like antipasti. Alternatively, you can reheat them in the microwave at 50% power. I don't recommend freezing the leftovers.
The nutrition info assumes that about half the salt remains in the dish after blotting the zucchini dry.