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For the casserole:
2 lb. green beans
salt to taste
cracked black pepper to taste
1 lb. oyster mushrooms, chopped
2 tbsp olive oil
6 tbsp butter (or vegan butter)
1 tsp thyme leaves, ~5-6 sprigs
3 tbsp all-purpose flour
For the topping:
NOTE: If time allows, make the infused oil/butter the day before. After cooking the shallots and garlic in oil, cut the heat and let them sit in the oil over night. The next day, remove them and then add the panko and other ingredients.
2 tbsp olive oil
2 tbsp butter
4 garlic cloves, roughly chopped
2 shallots, roughly chopped
1 tsp salt
2 tsp onion powder
1 tsp garlic powder
Preheat oven to 375 degrees.
Place a skillet over medium-high heat and add 2 tbsp olive oil and 6 tbsp butter. Once hot and the butter is melted, add oyster mushrooms. Cook until browned and all water has evaporated. Add the thyme leaves and cook for another minute. Add all-purpose flour and cook for another 2 minutes until the flour has a toasty smell. Add the non-dairy milk, pepper, and salt, and whisk until smooth. Once the sauce thickens, taste to adjust for seasoning and remove from heat.
Place a large stock pot filled 3/4 way with water and bring to a boil. Once boiling, heavily salt the water and add the green beans. Cook for about 1-2 minutes, or until vibrant and green. Transfer to an ice bath or undercook slightly if not preparing an ice bath. Drain the green beans.
Place the green beans in a 9x13 in. baking dish and pour the cream sauce on top. Toss the green beans in the sauce and spread them into an even layer. Wrap the dish in foil tightly and bake for 25 minutes.
While baking, place a skillet over medium-high heat. Add 2 tbsp olive oil and 2 tbsp butter. Once hot, add the garlic and shallots and cook until fragrant and browned, stirring frequently to prevent the garlic from burning, ~10 minutes. Remove the shallots and garlic and to the hot oil, add the panko, salt, onion powder, and garlic powder. Toast the bread crumbs for 2 minutes.
Remove the green beans from the oven and remove the foil. Spread the bread crumbs evenly on top of the green beans and bake for another 15 minutes until the bread crumbs are golden brown.
Let cool for 10 minutes to set. Bottoms up!