No need to bust out the cans this year. This is how you can make the classic casserole dish from scratch.
1) Wash your green beans, trim off the ends, and chop them in half.
2) Dunk the green beans in a pot of boiling, salted water for about 90 seconds. They should turn bright green and be slightly tender. Drain the beans and immediately dunk them in a bowl of salted ice water to stop them from cooking.
3) Slice up mushrooms, de-thaw your pearl onions, mince the garlic and herbs.
4) In a large pot over medium-high heat, melt the butter and then add the mushrooms and a pinch of salt.
5) Cook for about 5 minutes until the mushrooms start to break down and release their liquid. Then add garlic, pepper flakes, and herbs. Stir and cook for 30 seconds.
6) Add flour to the pot, stir, and cook for another minute to cook out the flour flavor.
7) Stir in the chicken stock in small batches. Don’t just add it all at once. Stir it constantly as you add the stock so it stays creamy and doesn’t get lumpy. If it’s too thick, add more stock or water. If it’s too thin, just simmer for a few minutes until it thickens.
8) Add green beans and pearl onions and stir to combine.
9) Pour mixture into a buttered casserole dish and top with Parm, breadcrumbs, and slivered almonds.
10) Bake at 400 degrees for about 20 minutes until the top is nicely browned.
11) Let cool for a few minutes and serve immediately.