Caramelized onions in the Instant Pot: How to make easy French onion soup, French onion dip sandwiches, and French onion cheese fries

French onion dip sandwich

I love the simplicity of this recipe, which capitalizes on the fact that you can make caramelized onions in the Instant Pot. Pressure cooking gives you a head start on caramelizing your onions. Afterward, when you open your IP, you will find cooked onions swimming in a surprising amount of liquid. At this point, drain off this delicious broth into a separate bowl. Your onions are cooked, but they still need more caramelization time. A ten minute sauté in the IP with frequent stirring will get you there with much less hands-on time than in the traditional method of caramelizing onions. 

French onion cheese fries topped with crispy jalapenos

Once you have these caramelized onions and oniony broth, the possibilities are almost endless. You can simply mix these back together for French onion soup. Or you can spread the caramelized onions onto a warm sandwich with melted swiss, and dip it into the broth. The caramelized onions/broth store and freeze well. The day after making this, we were feeling decadent and topped homemade fries with swiss cheese and caramelized onion gravy!

Notes: If you're like me and want to minimize onion house smells, I have a couple of tips. I slice the onions in my food processor to speed things up and minimize crying time. I run the Instant Pot in the garage or even outside, and do the pressure release out there, too. Then I bring it back into the house to do the sautéing and finishing touches. 

We are pescatarian and love mushrooms, so sometimes we add them to lend a meatier, heartier flavor. This is totally optional. 

For French onion soup mixture:

• 2 T butter
• 3 lbs yellow onions, sliced
• 7-10 garlic cloves (optional)
• 4 oz sliced mushrooms (optional)
• 1 t dried thyme leaves
• 1/2 t dried rosemary leaves (optional)
• 1 T and 1 t Better than Bouillon (I use Better than Bouillon "no beef" flavor)
• 1 1/2 t Worcestershire sauce (optional)
• 1 1/2 T red wine vinegar
• salt and pepper to taste

Dump all ingredients except vinegar and salt and pepper into IP. Seal lid and pressure cook for 4 minutes. It may seem weird to start pressure cooking without melting the butter or adding liquid, but don't worry, the butter will melt and the onions will produce plenty of liquid before coming to pressure. Quick release pressure when done.

When you open the IP, there will be 3-4 cups of liquid. Pour this into a separate bowl, add vinegar and add salt and pepper if needed. Set aside. 

Next, sauté the already cooked onions (and garlic and mushrooms if using) in the IP on high to caramelize them, stirring frequently. This will take about 10 minutes. 

Your onion mixture is ready to go! Now you can choose your adventure:

1. French onion soup. Reunite the onions and their broth to make soup. Top with bread and swiss cheese, broil, and serve!

2. French onion dip sandwiches. Spread the caramelized onions on French bread or a hoagie roll, top with a copious amount of gruyere cheese, and then toast or bake until the cheese is melted and the bread is crusty. Serve with a ramekin (or bowl, who are we kidding?) of the oniony broth for dipping! 

3. French onion cheese fries. Prepare fries in the oven. We hand cut and oven roast ours. Pile on a plate, top with gruyere, and return to oven and allow residual heat to melt the cheese. Stir some onion broth into your caramelized onions to make a thick gravy. Once cheese is melted, pour gravy on top, put on your stretchy pants, and enjoy!