Learn how to make an incredible Instant Pot green bean casserole with homemade creamy mushroom sauce and crispy fried onions. Perfect side dish for the holidays or Sunday roast!
When it comes to green bean casseroles, it's easy to go with the lazy option of using pre-made canned mushroom soup for the sauce. But we wanted to make this delicious side dish from scratch with whole ingredients. It tastes so much better, in our opinion, and is super easy. We even made our own crispy fried onions with gluten-free flour (not in the Instant Pot!) and the whole dish came together in under 30 minutes from start to finish.
How To Make Instant Pot Green Bean Casserole
Using the Sauté function of the Instant Pot, we cooked the base for our sauce - soft, buttery onions and mushrooms - before adding in the rest of the ingredients and setting the pressure to Manual for all of 1 minute. Seriously, the beans need very little pressure cooking, so this is a quick and easy dish to make for the table.
How To Make Crispy Fried Onions
Using gluten-free, grain-free tapioca flour and some seasoning for the coating, we pan-fried the onions in a generous amount of coconut oil (you can use other oil if you like) until golden and crispy on both sides. They serve as a gorgeous garnish on our finished casserole and add a lovely crispy texture and extra flavour to the dish.
You can use regular flour or another type of gluten-free flour, you have on hand. By all means, you can also sprinkle the casserole with store-bought crispy fried onions, like these ones.
Dairy-free: For a Whole30 and dairy-free/vegan version, use ghee or olive oil instead of butter and coconut cream instead of regular cream.
MORE INSTANT POT VEGETABLE RECIPES
- Instant Pot Green Beans with Butter & Cracked Pepper
- Instant Pot Scalloped Potatoes
- Instant Pot Baby Dill Potatoes
- Instant Pot Cabbage
- Instant Pot Black-Eyed Peas (Southern Style)
- Instant Pot Whole Cauliflower
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Instant Pot Green Bean Casserole
- 0.7 oz. butter about 2 tablespoons or 20 g
- 1 large onion peeled, halved and sliced thinly
- 1.5 teaspoons sea salt
- 7-8 oz. button mushrooms 200 g
- 1.3 lbs. green beans tails cut off, 600 g
- 2 large cloves of garlic finely diced
- ½ cup vegetable stock
- 1 teaspoon Dijon or yellow mustard
- 4-5 tablespoons crème fraîche or sour cream
For the crispy fried onions
- 1 medium onion peeled and sliced into thin rings
- 2 tablespoons tapioca flour or regular flour
- 1 teaspoon onion powder optional
- ½ teaspoon salt
- Generous pinch of pepper
- Turn on the Instant Pot and press the Sauté function key. Add butter and onions to the inner pot and cook for 5 minutes, until softened and golden brown and make sure to stir a few times. In the meantime, slice up the mushrooms, and prepare the beans. Rinse the beans under cold water and slice some of them (about a half) in halves.
- After 5 minutes, add the sliced mushrooms to the onions and season with 1.5 teaspoons of salt. Cook for 5 more minutes, stirring a few times. Then press Keep Warm/Cancel to stop the cooking process.
- Add the green beans, garlic, stock and mustard to the pot and stir through. Place the lid on top and lock, making sure the steam releasing handle is pointing to Sealing. Set the settings to Manual, High pressure, and change the timer to 1 minute. After three beeps the Instant Pot will begin to build up the pressure and start cooking. Keep in mind that the cooking process starts while the pressure is building up and that's why we're only setting the cooking time to 1 minute.
- Once the cooking finishes, use the quick release method (simply move the release handle to venting and step away) to let off the built up steam and pressure. If you leave the pot to release the pressure naturally, the beans will continue to cook and might turn out a little softer than you like.
- Open the lid carefully. Add the crème fraîche or sour cream to the beans and stir through until well combined.
- Prepare the crispy fried onions while the casserole is cooking. Place the onion rings into a bowl and sprinkle with flour, onion powder, salt, and pepper. Using your hands, toss the rings through the flour coating them evenly. Heat a thin layer of coconut oil (about 3 tablespoons) or your preferred oil in a deep frying pan over medium-high heat. Once hot, add the flour coated onions rings and cook for 3-4 minutes each side, turning them with tongs to allow even browning. You may need to separate some of the rings and flip them over more than once. Finally transfer to a plate and sprinkle with some salt.
- Transfer the cooked green bean casserole into a serving dish and top with the crispy fried onions. Sprinkle with some extra black pepper.