One Mean Green Bean Casserole
Prep time
Total time
Serves: 4
  • 600g green beans- halved and rinsed
  • 700ml milk
  • 1 small onion
  • 1 bay leaf
  • 2 garlic cloves-smashed
  • 1 small whole nutmeg
  • 45g flour
  • 45g butter + 1 tablespoon for the mushrooms
  • 240g chestnut mushrooms
  • 2 large red onions
  • 1-2 tablespoons vegetable oil
  • Parmesan for sprinkling- Optional
  1. Rinse the green beans well. Place them in a deep pot, cover with water and bring to a boil. Blanch them for no more than three minutes. Remove, strain and leave for later. You can do this step well ahead of time and then re-heat the beans in a little water when ready to serve.
  2. As soon as you put the beans on the stove, add the milk to a saucepan with the whole nutmeg, bay leaf, onions and smashed garlic. Bring the milk to a simmer and be sure to keep stirring so that it doesn’t burn. This shouldn’t take more than two to three minutes. Turn off the flame and let it sit to infuse about 15 minutes. After 15 minutes, remove all the ingredients from the milk.
  3. In a well buttered pan, add the mushrooms and cook on high flame for no more than a minute or so. Remove and strain.
  4. Add the butter (45g) in a heavy bottomed sauce pan and let it melt on medium-low flame.
  5. Now, add the flour (45g) and using a wooden spoon keep stirring till all is incorporated.
  6. You are going to keep stirring for about 2-3 minutes till the roux starts to froth and most of the flour flavor is cooked off.
  7. Now begin adding the strained warm milk a little at a time. About 1-2 tablespoons to start with and continuously stir.
  8. Switch to a whisk and keep adding the milk slowly, continuously whisking, adding more as the milk is incorporated.
  9. Once you’ve added all the milk, let the sauce cook for a further ten to fifteen minutes on low heat and keep stirring very often. Now, if you wish you can make the sauce a couple of hours ahead of time then you will need to keep it warm in a bain-marie. Add the sauce to a pyrex bowl and place over a pot filled with warm water. The sauce will thicken so just before serving add more warmed milk to it while whisking till desired consistency is reached. Remember to add the milk little by little. You can also cook the roux the night before, keep it in the fridge covered, then follow the rest of the steps about twenty to thirty minutes before serving. Make sure you start with a warmed roux.
  10. Now add salt and freshly ground pepper.
  11. The mushrooms. Be sure to warm them if you’re making this ahead.
  12. Now, drizzle the vegetable oil into a sautee pan and when the oil is hot, add the onion rings. Cook, stirring very often, till they are golden and crispy.
  13. Lather the hot green beans with the bechamel sauce. Sprinkle with some parmesan if you like.
  14. And, then top with the crispy onions. Alternatively and if you are making certain bits ahead of time, you can add all the chilled ingredients in a casserole, add the bechamel sauce and then bake in a pre-heated oven 350F/160C/3G for about 10-15 minutes.
  15. Enjoy!
Recipe by Bethany Kehdy at