The Flexibility of a Slow Cooker 

I love my slow cooker—it frees my hands (and oven) for hours, and the cook time is always forgiving. Fill it with ingredients, put the lid on, and let it do its thing. It doesn’t get much easier than that!  Most slow cookers have three settings: high, low, and warm. I start most slow cooker recipes on high and reduce to low if I want to draw out the cook time. This recipe needs at least 2 hours on high to get the green beans tender, but cooking it for longer makes it even better—the flavors meld and the sauce cooks down and concentrates a bit more. Then, I shift it to warm when everything inside is fully cooked, but I want to keep it warm until ready to serve. On the warm setting, the green bean casserole will hold for 4 to 5 hours, which is great for when your guests graze on the food throughout the party.

Using Fresh, Blanched Green Beans

You can use frozen green beans, but I recommend using fresh, if you have them. You will need to blanch them before adding them to the slow cooker.  What is blanching? It means cooking the green beans in boiling water for a few minutes until they’re vibrantly colored and crisp-tender, then shock them in an ice bath—this stops any further cooking from residual heat and locks in the flavor. You do not need to blanch frozen green beans.

A Simple Homemade Mushroom Cream Sauce

I have a friend who is a diehard fan of classic green bean casserole—only store-bought French’s Fried Onions sprinkled on top scratch that nostalgic itch for her. But even she admits that homemade mushroom cream sauce is a game changer and far more delicious than the canned stuff. And it couldn’t be simpler to make.  Start by cooking your mushrooms in a bit of butter. I typically use cremini mushrooms—they are small, tender, and have a subtle meaty flavor., You can use a mix of mushrooms: button, portobello, chanterelle, and even a few morels would be delicious. I’d avoid shiitake mushrooms because they are too chewy for this recipe. Once the mushrooms are cooked, add a bit of flour to make a roux—a combination of butter and flour used to thicken the sauce—and then add some chicken stock and cream. That’s it! The mushroom sauce can be made ahead and stored in the fridge for up to 5 days or in the freezer for 2 months. 

Fry Your Own Shallots

I prefer crispy shallots to onions on top of my green bean casseroles—they are crispier when fried and don’t even need a batter. without a batter.  The trick to ultra crispy shallots is to slice them as thinly as possible. Start them in cold oil. They’ll get crispy in no time, so stir them regularly and keep a close eye on them. Once they become golden brown, drain the fried shallots on a paper towel. And try not to snack on too many while your casserole cooks!  The fried shallots can be stored in an airtight container for up to 1 month.  Don’t have time to fry your own shallots? I keep a jar of store-bought shallots in my cupboard at all times. I find them at my local Asian grocery store. Of course, French’s Fried Onions always works too.

Swaps and Substitutions

This recipe uses chicken stock, but you can easily make it vegetarian by swapping out vegetable stock or, even better, mushroom stock.Looking for a vegan casserole? Use vegan butter, like Earth Balance, and unsweetened cashew milk instead of the half and half. Is it a green bean casserole without green beans? Probably not. But blanched broccoli or cauliflower would be delicious swaps regardless. 

For the Love of Green Beans

French Green Beans with Butter and Herbs Creamy Green Beans and Mushrooms Green Beans with Almonds and Thyme Stir Fried Green Beans with Ginger and Onion Green Beans with Salsa

1 pound (about 8 medium) shallots, very thinly sliced 2 cups vegetable oil

Fill a large mixing bowl with ice water and set aside (this is your ice bath). Drain the green beans and immediately plunge them into the ice bath. Once cooled, drain the green beans again and set aside. Add the soy sauce, red wine vinegar, and a few crack of black pepper. Stir well and taste the sauce, you may want to add more salt. I store my leftovers directly in the slow cooker—just put the lid on and clear some room in the fridge—for up to 5 days. To reheat, return the pot to the base and heat on low for about 1 hour. Did you love the recipe? Leave us stars below!