Lay zucchini skin side down on a paper towel lined baking sheet. Season with kosher salt and let sit for 20 minutes. Blot the top with paper towels to remove moisture.

Preheat oven to 350F. Heat ¼ cup olive oil in a frying pan over medium heat. Once hot, place zucchini flesh side down—you should hear a sizzle; if not, remove zucchini and let the oil heat more.

Cook zucchini until flesh begins to turn golden brown, about 8-10 minutes. Transfer the skillet to the oven and cook for 10 minutes.

Flip zucchini so the flesh side is up and cook for another 10 minutes.

While zucchini cooks, add feta, lemon juice, lemon zest, and ½ cup chopped mint to a food processor. With the machine running, drizzle in olive oil until you reach your desired creamy consistency.

Remove zucchini from oven. Plate with dollops of minted whipped feta, place zucchini on top, and garnish with crushed pistachios, julienned mint, flaky salt, lemon zest, and sumac. Serve immediately.