- 1/4 cup extra-virgin olive oil
- 2 teaspoons kosher salt, plus more to taste
- Vegetable oil, for frying
- 24 zucchini blossoms, stamens removed
Whisk flour and olive oil in a large bowl to combine (dry, pea-size balls will form). Add 3/4 cup warm water; whisk until a smooth, thick pancake-like batter forms. Whisk in 2 tsp. salt. Let batter rest, uncovered, at room temperature for 1–2 hours.
Pour vegetable oil into a large heavy high-sided skiller to a depth of 1/2". Prop deep-fry thermometer in oil so bulb is submerged. Heat over medium heat until thermometer registers 375° in a heavy, high-sided large skillet until a candy-thermometer attached to side of skillet registers 375°.
Beat egg whites until medium-stiff peaks form; gently whisk one third of the white into batter to loosen, then gently fold in the rest of the whites until just incorporated.
Working in batches of 6, dip blossoms in batter, letting excess batter drip back into bowl. Fry, turning occasionally, until golden and crispy, 3–4 minutes per batch. Transfer to paper towels. Season with salt; serve hot.