Green Bean Casserole
Green beans in a creamy mushroom sauce under a crown of crispy fried onions, made from scratch instead of from a can.
- Preparation
- 25 min
- Cook/bake time
- 55 min
- Total
- 1 hr 20 min
- Difficulty
- Easy
- Calories
- 266 kcal
- Servings
- 8
- Prep
- 25 min
- Cooking & baking
- 55 min
Green beans in a creamy mushroom sauce under a crown of crispy fried onions, made from scratch instead of from a can. The beans are blanched and shocked in ice water so they stay green instead of turning olive. The crispy fried onions are only added on top in the final minutes, otherwise they will be soft before the casserole is done.
Why this works
The beans are briefly blanched and immediately shocked in ice water. The short cooking time destroys the enzymes that break down chlorophyll, and the cold stops the cooking process, which is why they stay green instead of olive. In the sauce, the crucial moment is when the mushrooms stop squeaking and start to brown. Only when their water has evaporated can the flour thicken properly, otherwise the sauce remains thin and becomes watery in the oven. And the crispy fried onions only belong on top in the final minutes because they will turn soggy within ten minutes in moist heat.
Step-by-step instructions
- 1
Blanch the beans
Boil the beans in heavily salted water for four to five minutes until they still have a distinct bite, and immediately pour them into a bowl of ice water. Leave them there for two minutes and then drain them well. Without the ice water, they will continue to cook in the residual heat and lose their color in the oven.
- 2
Sauté the mushrooms properly
Sauté the mushrooms in the butter over high heat without overcrowding the pan. They will first release water and squeak, then the water evaporates and they start to brown. Only from this point on are they ready. Add the onion and garlic and sauté them for two minutes.
- 3
Thicken the sauce
Sprinkle the flour over the mushrooms and stir for one minute until it no longer smells like raw flour. Pour in the milk and heavy cream in three portions and stir until smooth after each addition, then let the sauce simmer for five minutes until it coats the back of a spoon. Season to taste with soy sauce, thyme, nutmeg, salt and pepper. The soy sauce provides the depth that the canned soup usually delivers.
- 4
Layer the casserole
Mix the drained beans with the sauce and pour everything into a greased baking dish of about 30 cm. Sprinkle one third of the crispy fried onions into the mixture, which adds depth of flavor. The sauce should coat the beans, not have them swimming in it.
- 5
Bake and crisp
Bake the casserole at 200 °C top and bottom heat for twenty minutes until it is bubbling around the edges. Then sprinkle the remaining crispy fried onions on top and bake for another five to seven minutes until they are golden brown and crispy. Serve immediately, as the crust does not stay crispy for long.
Our best tips
- Do not skip the ice water. It is the only reason why the beans are still green after baking.
- Sauté the mushrooms in two batches if the pan is small. Too many at once means boiling instead of frying.
- Only add the crispy fried onions in the final minutes. If baked from the beginning, they become soft and taste soggy.
Tasty variations
With Bacon
Render 100 g of diced bacon and sauté the mushrooms in the bacon fat. Then reduce the butter to 20 g.
Vegan
Replace the butter with oil, and the milk and heavy cream with oat cream. The sauce stays creamy but needs a little more nutmeg and salt.
Nutrition facts
| Calories | 266 kcal |
|---|---|
| Protein | 7 g |
| Carbohydrates | 20 g |
| – of which sugar | 8 g |
| Fat | 17 g |
| Fiber | 4 g |
Where the 266 kcal come from
per serving
Calculated from the ingredients – how we do it
We add up reference values for every ingredient and divide by the number of servings. These assumptions are baked in:
- Reference values per 100 g – for the raw ingredient, exactly as listed.
- Tinned goods count at drained weight, bone-in meat at purchase weight: you eat about 70 per cent of a chicken thigh and leave the rest.
- Water evaporates as you cook. The energy stays in the pot, the weight does not – so the figure is per serving, not per 100 g of finished dish.
- Anything listed without a quantity – “salt and pepper” – is not counted.
A guide value, not a lab measurement: no two onions weigh the same, and fat content varies from pack to pack.
Frequently asked questions
Can I prepare the casserole in advance?
Yes, you can prepare it up to the layering step a day in advance and refrigerate it. Straight from the fridge, it needs about ten minutes longer in the oven. The crispy fried onions are only added at the end either way.
Can I use frozen beans?
Yes, but shorten the blanching time to two minutes, as they are pre-cooked. Canned beans also work, but they become soft and lose all structure in the oven.
Why did the sauce become watery?
The mushrooms did not release their water before the flour was added. Wait until they actually brown, which is the point from where the thickening holds.
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