Green Bean and Peas Casserole

Green Bean Casserole is an American classic. For decades, people have been enjoying it at Thanksgiving, at potlucks, and as a dinner side. Green Bean and Peas Casserole, though? That’s a Cecilia Classic.

Peas 

Peas do not belong in a green bean casserole. They have never been invited to the party. But I love them. Like, really love them. They are sweet, cheap, and go so well with everything. When I first started hosting Thanksgiving dinner in Sweden, I was only using green beans in the casserole, obviously. But they can get pretty expensive here, especially the fresh ones. I was looking for a way to stretch the dish a bit without changing it too much and decided peas would be the perfect addition. It was so delicious that I decided to do it every year.

Non-Traditional 

There are actually many things about this dish that are non-traditional. The original calls for a couple of cans of canned green beans mixed with a can of Campbell’s cream of mushroom soup. This gets baked and topped with Funyuns, onion-flavored chip-like things (think cheese doodles but onion-flavored, not cheese). I have never actually had this version.

Culinary School 

The first time I tried “Green Bean Casserole” was in culinary school. I went to Ballymaloe Cookery School in Co. Cork, Ireland. We had a bunch of other Americans in the course, and as Thanksgiving approached, they did a lesson on how to make certain American dishes. We covered the turkey, cranberry sauce, and green bean casserole. But their version was 100% homemade. Creamy mushroom sauce, perfectly blanched green beans, all topped with crispy fried shallots—it was a revelation! Rich, creamy, delicious—“how could I have never had this before?!” I thought to myself. I was sold, and from that day forward, I have always had green bean casserole on my Thanksgiving table.

Fried Shallots 

It is very, very important not to take the shallots too dark in the oil. Make sure they are a light golden brown, as they continue cooking a bit while sitting on the paper towel. And don’t forget to save the shallot oil! It is delicious and can be used as a flavorful alternative to cooking oil. I especially like it in stir-fries.

Alternatives 

My version is topped with a breadcrumb topping. This is untraditional, and you can skip it if you like. A Swedish twist I sometimes add is using foraged mushrooms like chanterelles or yellowfoots in place of the fried button mushrooms in the sauce. And, of course, you can skip the peas if you wish.

Regardless of how you serve this dish, it is delightful, and your guests will love it. It will surely become a staple at your Thanksgiving dinners, as it has become at mine.

Print Recipe

Green Bean and Peas Casserole

Ingredients

Mushroom Sauce

• 60 g butter
• 170 g onion finely chopped
• 300 g mushrooms thinly sliced
• 200 g mushrooms grated
• 500 g cream
• Salt and freshly ground pepper
• Lemon juice
• Freshly chopped parsley

Fried Shallots

• Shallots thinly sliced
• Oil

Breadcrumb Topping

• 200 g Breadcrumbs
• 6 Tbsp shallot oil reserved from frying shallots
• ½ t salt
• ¼ t pepper
• 1 Tbsp garlic powder optional
• 1 Tbsp finely chopped parsley or sage or both optional

Green Beans and Peas

• 500 g frozen green beans
• 250 g frozen peas

Instructions

Mushroom Sauce

• Thinly slice 300g of mushrooms.
• In a frying pan, heat a teaspoon each of butter and oil over medium heat.
• Add a thin layer of the sliced mushrooms, avoid overlapping as much as possible.
• Season with a pinch of salt and cook until the mushrooms turn nicely brown and crispy. Season with salt and a bit of lemon juice then remove from the pan.
• Repeat the process with the rest of the sliced mushrooms.
• Finely dice the onion and add the remaining butter to the pan. Sweat the onion until sweet and translucent.
• Add the grated mushrooms and fry until the water has evaporated and they start to brown.
• Pour in the cream and cook together for about 3 minutes.
• Remove from heat and season with lemon juice, salt, and pepper.
• Blend with either a hand blender or in a standing blender for a smooth sauce.
• Fold in the fried mushrooms and chopped parsley.
• You can use it immediately or store it in the fridge for later use.

Fried Shallots

• In a wide frying pan or pot, pour enough cold oil to allow the shallots to float.
• Slowly fry the thinly sliced shallots over low heat until they turn light golden. They continue to cook a bit out of the oil so don’t take them too dark in the pan.
• Remove the shallots from the oil immediately and drain on paper towels.
• Spread them out and season with salt.

Breadcrumb Topping

• Mix the breadcrumbs with the reserved oil from frying the shallots. The mixture should be sandy but not too wet.
• Season to taste with salt, pepper, garlic powder (if using), and finely chopped herbs. Set aside.

Green Beans and Peas

• In a large pot of boiling salted water (like pasta water), cook the green beans for 2-5 minutes until they reach your desired doneness. You can go for al dente or softer, depending on your preference.
• Immediately transfer the cooked green beans to an ice bath to stop the cooking process. Strain and remove excess water.

Assemble and Bake

• Preheat your oven to 375°C (190°C).
• Mix together the cooked green beans, peas, and mushroom sauce. Pour the mixture into a casserole pan.
• Sprinkle the breadcrumb topping evenly over the top.
• Bake the casserole in the preheated oven until the breadcrumb topping turns golden brown, approximately 30-40 minutes.
• Once out of the oven, garnish the casserole with the fried shallots.

Notes

I like to make my own breadcrumbs by blitzing any leftover Plain White Loaf bread cubes I have from making Dad’s Famous Thanksgiving Stuffing.
You can omit the breadcrumb topping and fried shallots if desired.
The recipe calls for 170g of onion, this is approximate and equals about two medium onions. It doesn’t need to be exact, just in the ballpark.
If you don’t want to add in the peas, use 750g of green beans.