01 -
Turn the oven on to 350º. Chop up mushrooms and mince the garlic.
02 -
In a large pan over medium heat, heat up the olive oil. Throw in the mushrooms, sprinkle with some salt and pepper, and let them cook until soft. Stir in minced garlic and cook until the liquid evaporates.
03 -
Melt the butter in the pan and throw in the flour. Keep stirring until it forms a thick paste and turns lightly golden (takes about 2 minutes).
04 -
Add the stock, milk, and garlic powder to the pan. Stir thoroughly, scraping up any cooked bits stuck to the pan. Cook until the liquid thickens slightly and starts bubbling.
05 -
Drop cream cheese into the thickened sauce. Stir constantly till it's completely smooth and melted.
06 -
Toss the frozen green beans into the pan. Mix them through the sauce and cook until they're heated and everything is bubbling gently. Taste and adjust the salt and pepper if you need to.
07 -
Fold a quarter of the crispy onions into the mixture. Empty everything into a baking dish, then sprinkle the rest of the onions over the top.
08 -
Bake for about 20 to 25 minutes, until the onions on top are toasty and the edges of the dish are bubbling.