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Summer Squash Flatbreads

Summer Squash Flatbreads
Celebrate the summer squash harvest with these delectable savory flatbreads, made instantly tangy with a boost from Platinum Instant Sourdough Yeast.
Yield 2 flatbreads



  • 3 3/4 cups (469g) all-purpose flour, divided
  • 1 (0.63oz) package (18g) Platinum Instant Sourdough Yeast
  • 2 1/4 teaspoons (6.75g) kosher salt (see note 1)
  • 3/4 cup (180g) water
  • 1/2 cup (120g) whole milk
  • 3 1/2 tablespoons (49g) extra-virgin olive oil, divided
  • 1 teaspoon (7g) honey
  • 3 cloves (15g) garlic, minced
  • 1/2 teaspoon packed lemon zest
  • Cornmeal (for dusting)
  • 1 1/2 cups (170g) shredded fontina cheese
  • 2/3 cup (61g) finely shredded Parmesan cheese
  • 1/2 cup (60g) thinly sliced (1/16 inch) zucchini
  • 1/2 cup (60g) thinly sliced (1/16 inch) yellow squash
  • 1/2 cup (65g) thinly sliced red onion
  • Garnish: shredded fontina cheese, flaked sea salt, fresh basil leaves, chopped fresh parsley


  • In the bowl of a stand mixer fitted with the paddle attachment, beat 2 cups (250g) flour, Platinum Instant Sourdough Yeast, and kosher salt at low speed until well combined.
  • In a small saucepan, heat water, milk, 2 tablespoons (30g) oil, and honey over medium heat until an instant-read thermometer registers 120°F (49°C) to 130°F (54°C). Add milk mixture to flour mixture; beat at medium speed for 2 minutes. Reduce mixer speed to low; gradually beat in 1 1/2 cups (188g) flour until a very soft, sticky dough is formed.
  • Switch to the dough hook attachment. Beat at medium-low speed for 13 minutes. (Dough should almost pull away from sides of bowl.) Add up to remaining 1/4 cup (31g) flour, 1 tablespoon (8g) at a time, if necessary. (Avoid adding too much flour; a slack dough is important for a light, airy crust.) (Dough should pass the windowpane test; see note 2.) Using well-floured hands, shape dough into a ball.
  • Lightly oil a large bowl. Place dough in bowl, turning to grease top. Cover with plastic wrap, and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, about 1½ hours.
  • Punch down dough. Divide dough in half (about 390g each). Using floured hands, shape each half into a smooth ball, and place each in a lightly oiled small bowl. Lightly brush tops with oil. Cover with a double layer of plastic wrap, and refrigerate overnight (see note 3).
  • About 1½ hours before baking, remove dough from refrigerator. Place a pizza stone on lowest oven rack. Preheat oven to 475°F (250°C). (Allow at least 1 hour for pizza stone to fully heat before baking.)
  • In a small microwave-safe bowl, combine garlic, lemon zest, and remaining 1 1/2 tablespoons (21g) oil. Heat on high until mixture begins to bubble, about 20 seconds.
  • Generously dust a pizza peel or a rimless baking sheet with flour and cornmeal.
  • For each flatbread, drape each portion of dough over your knuckles. Using both hands, gently stretch dough with knuckles to form a 3/8-inch-thick oval, being careful not to press out any air bubbles. Place dough on prepared pizza peel, stretching to even out any thick areas. Shake pizza peel a few times to make sure dough always stays loose, dusting bottom with additional cornmeal if needed. (Continue to check dough a few times while topping. Dough must remain loose to slide easily onto pizza stone.)
  • Evenly spoon half of garlic mixture onto each flatbread. Top each with half of fontina and half of Parmesan; top each with half of zucchini, half of squash, and half of onion. Slide 1 flatbread onto hot pizza stone.
  • Bake until crust is deep golden brown, 10 to 12 minutes, using tongs to rotate flatbread halfway through baking. Immediately garnish with fontina, sea salt, basil, and parsley, if desired.
  • Repeat procedure with remaining flatbread. Immediately garnish with fontina, sea salt, basil, and parsley, if desired.


  1. Salt weight and volume vary by brand. Diamond Crystal kosher salt was used in this recipe (1 tablespoon is 9 grams). If you a have different brand or type of salt, use the weight listed in the recipe, not the volume measurement. If you do not have a scale, check your brand’s website for what the equivalent volume measurement is for the weight listed in this recipe.
  2. Test dough for proper gluten development using the windowpane test. Using floured fingers, pinch off a small piece of dough. Slowly pull the dough out from the center. If the dough is ready, you will be able to stretch it until it’s thin and translucent like a windowpane. If the dough tears, it’s not quite ready. Beat for 1 minute, and test again.
  3. Refrigerating this dough overnight allows it to develop better flavor and texture, but the flatbreads can be baked on the same day as well. Simply preheat pizza stone and oven while dough is rising and then shape flatbreads after punching down dough.
Recipe by Bake From Scratch.

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Review & Comments

Peg | Reply

5 stars
Can you use regular instant yeast?

Red Star Yeast | Reply

Hi Peg – Yes, use 1 packet (1/4-ounce) or 2 1/4 teaspoons of instant yeast.
Happy baking!

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