Zucchini & Caramelized Onion Gratin
Author: 
Recipe type: Vegetable, Side Dish
Cuisine: Summer, Italian
Prep time: 
Cook time: 
Total time: 
Serves: 6-8
 
If you'd like to turn the zucchini gratin from side dish to main, you could add a layer of eggplant and serve it with a simple tomato sauce.
Ingredients
  • 2 Tbsp. Butter
  • 2 Tbsp. Olive Oil, plus more for the pan
  • 3 large Yellow Onions, thinly sliced
  • 1 tsp. fresh Thyme
  • 5 medium Zucchini, very thinly sliced (I used my mandoline set at ⅜ in.)
  • ¾ c. Breadcrumbs
  • 1½ c. grated Fontina Cheese
  • ¼ c. Parmesan Cheese
  • about 12 Anchovies OR a handful of flavorful Black Olives
Instructions
  1. In a large, wide sauté pan, melt the butter and olive oil together over medium-low heat. Add the sliced onion and slowly cook until the onions are golden and caramelized, about an hour. Season with salt, pepper, and the fresh thyme.
  2. While the onions are cooking, place the sliced zucchini in a large colander and toss with a scant teaspoon of kosher salt. Set the colander over the sink and allow the zucchini to drain while you wait for the onions, tossing periodically.
  3. Preheat the oven to 400°. Generously rub a pie plate with olive oil. Add about ¼ c. of the breadcrumbs and shake them around until the pan is well coated. Now start building the gratin. Have a few paper towels handy and gently blot the moisture off the zucchini as you work (soggy zucchini dishes are the reason lots of people think they hate zucchini!). Make a base layer of overlapping zucchini slices. Spread with about ½ of the caramelized onions, sprinkle with about ½ of the Fontina, and repeat. Finish with a layer of zucchini. Sprinkle with the breadcrumbs and Parmesan, then drizzle with a little olive oil. Top with anchovies or olives.
  4. Cover the gratin with a sheet of foil with holes poked in it, taking care that the foil does not touch the cheese. Bake until the zucchini is tender when poked with a sharp knife, about 35 minutes. Remove the foil and bake for another 5 minutes to crisp up the topping. Allow to cool for a few minutes before serving or cool to room temperature.
Recipe by strawberryplum at http://www.strawberryplum.com/zucchini-caramelized-onion-gratin/