Green bean casserole is a quintessential Thanksgiving side dish. Topped with crispy onions it is totally irresistible!
Course: Side Dish
Author: Lucy Parissi
6tbspunsalted butter plus more to butter the dish
600g| 1.3lbs green beanstrimmed
400g| 14oz chestnut button mushroomshalved or quartered
1large yellow onionpeeled and finely diced
240ml| 1 cup whole milk
120ml| 1/2 cup vegetable stockI used Kallo stock cube
2heaped tbsp plain flour
1tbspFrench’s yellow mustard
60g| 2oz grated Parmesan cheese
3tbspFrench’s crispy onionsfinely ground
3tbspFrench’s crispy onions to top
salt and freshly ground pepper to season
Blanch the green beans in boiling water for about 5 minutes then drain and plunge into a bowl of ice water until cooled. Drain and set aside.
Preheat the oven to 190C (375F).
Melt two tablespoons of the butter in a large skillet or frying pan. Sauté the onion until soft - 4-5 minutes.
Add the mushrooms and cook, stirring often, for a further 8 minutes. Season with salt and pepper and transfer to an ovenproof baking dish.
Add the remaining butter to the pan. Once butter melts, whisk in the flour to make a roux. Cook, stiring, for a couple of minutes.
Gradually stir in the milk and vegetable stock, whisking until the the mixture thickens. Stir in the mustard, Worcestershire and soy sauce. Check the seasoning and adjust if necessary. Cool completely.
Mix with the green beans and mushrooms, stirring thoroughly to combine.
Sprinkle with the ground crispy onions and Parmesan.
Cook, covered with foil, for about 50 minutes until bubbling.
Uncover and cook for a further 10 minutes.
Serve topped with crispy onions.
If preparing the dish in advance, follow the method until step 7, chill in the fridge overnight then top with the Parmesan and ground crispy onions just before baking.