French Onion Pizza

Put the flavors of French onion soup on a pizza! French onion pizza is topped with slow caramelized onions, gruyere cheese and a touch of fresh thyme.

The key to delicious French onion soup is the slow process at which the onions are caramelized and cooked.  Instead of making one of my favorite soups, I’ve decided to turn it into pizza!  

You may ask, why don’t you just make soup?  First, because I want to eat something that I can pick up with my hands and doesn’t require a plate or bowl. And second, pizza is always a good idea.

I made a mixture of olive oil and dried French thyme to act as the base sauce for this pizza. The thyme lends a nice sweet, earthy flavor that balances the caramelized onions and the salty gruyere.

Once you’ve cooked the onions, building the pizza is super simple. Over the years I’ve collected quite a few little cast iron pans.  

Ingredient Notes

Only a handful of ingredients are needed to make this delicious French onion pizza. You may opt to use store-bought pizza dough to save time. I highly recommend the refrigerated one pound pizza dough from Trader Joe’s.

• Pizza Dough: For the truly homemade, from-scratch experience, try this easy pizza dough recipe. The recipe makes enough for two 12-inch pizzas. Use one now and freeze the other for later! Or, try this two-ingredient pizza dough for a super simple, quick meal.
• Caramelized Onions: Sliced onions slowly cooked until caramelized, brown, and super flavorful. A key ingredient that packs a punch of flavor! More details in next section.
• Gruyère Cheese: Hard Swiss cheese with full-bodied and nutty flavors that melts well. It’s a balanced cheese that is slightly sweet and slightly salty. Best substitutes include mozzarella, fontina, or comté.
• Thyme: Aromatic herb with minty, lemon-like flavor. There are several varieties available including lemon thyme, French thyme, and garden thyme. Use either fresh or dried version.

Another way to incorporate French onion soup flavor into baked goods: caramelized onion and gruyere bread rolls!

How to Caramelize Onions

Caramelizing onions is a lengthy process, but very necessary to get that nice sweet flavor. Be patient.

It can take anywhere from 30 minutes to one hour to cook the onions. This recipe uses four pounds of onion. That may seem like a lot. However, keep in mind that onions significantly reduce in volume as it cooks.

Four pounds of sliced onions fills the entire 5-1/2 quart Dutch oven to the brim (as shown in the image above). After nearly 90 minutes of cooking, they will drastically reduce in volume (as shown in the image below).

The resulting caramelized onions are intensely flavorful and delicious.

While this is a time consuming process, the results well worthwhile. Just believe that some things are worth waiting for.  These onions are definitely one of those things.  Fast and easy, doesn’t always mean good.

Caramelizing takes time and shouldn’t be rushed.  Otherwise, you’ll likely end up with burnt onions.  Stir the onions every 8 minutes or so to make sure it doesn’t burn at the sides or bottom of the pan. 

This recipe makes four mini pizzas, which means each French onion pizza has about a pound of onion goodness!

There are two ways to caramelized onions: oven or stove-top.

• Oven Method: Preheat oven to 400 degrees F. Coat the inside of a 5-1/2 quart Dutch oven (or oven safe pot) with cooking oil. Add sliced onions, butter, and salt.  
  • Bake for 1 hour, covered.
  • Remove from oven and stir onions, making sure to scrape up any onions that have stuck to the sides of the pot. Return to oven with the lid slightly ajar.
  • Continue to bake for another 90 minutes until onions are light brown in color and onions have dramatically reduced in volume. About 45 minutes into cooking, stir onions to prevent any burning along the sides of the pot.
• Stove Top Method: Place sliced onions in 5-1/2 quart Dutch oven (or oven safe pot). Set over medium heat. Stir the onions every 8 minutes or so to make sure it doesn’t burn at the sides or bottom of the pan.  Process can take anywhere from 30 to 90 minutes. Season onions with salt once they are caramelized.

Cast Iron Pan Pizza

Cooking homemade pizza in a cast iron skillet pan is a game changer! You are able to achieve a crispy crust bottom and a chewy interior crust when you heat the dough using both stove and oven.

Cast irons pans are great at retaining and distributing heat. The cast iron mimics a pizza stone, allowing the dough to produce a nice, crispy crust. The pizza cooks more evenly because of the way the heat is distributed in the pan.  

One pound of pizza dough fits in an 8-inch to a 12-inch pan. The crust will be thicker in an 8-inch pan. Or, one pound of dough may be divided in four mini 5-inch pans.

I prefer to make my pizzas in cast iron pans because I find that’s the best way to obtain that nice round shape. See Pesto Pizza with basil salt for further explanation.  

Pizza Assembly Tips

• When it comes to toppings, less is more. Do not overload the pizza with cheese and toppings! It will weight down the center of the dough and prevent the pizza from baking evenly. 
• Assembling the pizza inside the skillet keeps the nice round symmetrical shape of the pizza. No need to worry about transferring the pizza with a pizza peel (which can be quite stressful!). 
• Remove the skillet from the oven. Allow pizza to cool for about 3 minutes before unmolding. Place pizza on a cutting board and slice into desired pieces. 

After baking the pizzas, your kitchen will smell warm, inviting, and utterly delicious!

More Homemade Pizza Recipes

• Summer Vegetable Pizza
• Mushroom Kale Pesto Pizza
• French Bread Pizza