green bean casserole (TOTALLY from SCRATCH)

this recipe is slightly adapted from THIS one by Guy Fieri...
where his calls for sour cream I substituted plain greek yogurt (I do this with most recipes that call for sour cream) ...his also calls for several different kinds of mushroom..I'm not a bajillionairre so I just used creminis (baby bellas) I suppose you could just use button mushrooms but the creminis do add more flavor...more notes below

Ingredients:

1 1/2 pounds green beans, trimmed (I think you could easily use frozen green beans and save yourself some time)
kosher salt and freshly ground black pepper
2 tablespoons unsalted butter
1 tablespoon vegetable oil
1 pound mixed gourmet mushrooms, cleaned and quartered
1/2 teaspoon fresh thyme leaves
2 cloves garlic, minced
1/4 teaspoon cayenne powder
1/4 teaspoon ground nutmeg
2 tablespoons all-purpose flour
1 cup low-sodium chicken broth
1 cup plain greek-style yogurt
1/2 cup heavy cream
1/4 cup grated parmesan
4 medium shallots, sliced and separated into thin rounds
1 cup all-purpose flour (seasoned with salt & pepper)
vegetable oil, for shallow frying

Directions

preheat the oven to 375 degrees F.

boil or steam the green bean until they turn bright green..just a few minutes. (you don't want to overcook the green beans..as they will also cook in the oven)
strain
add the butter and vegetable oil to a large cast iron or other large heavy pan over medium-high heat
once the butter is melted and the pan is hot, add the mushrooms. cook undisturbed so the mushrooms sear nicely (a minute or two) add the thyme and garlic and continue cooking the mushrooms to get a nice color.
season with the salt, pepper, cayenne and nutmeg.
cook a few more minutes...then dust the mushrooms with the flour..stirring with a whisk to incorporate (just like making a roux) gradually adding in the chicken stock
bring to a simmer, then reduce the heat and add the yogurt and cream.
stir gently and cook over low heat until gravy thickens, about 5 minutes.
add the green beans to the pan and fold together so everything is mixed well.
if you're using cast iron just spread the mixture out evenly in the pan..otherwise transfer to a greased casserole
sprinkle with the grated parmesan and bake until bubbly and the top is melted and golden

pour the vegetable oil into a deep skillet and heat to 350 degrees F. pour the seasoned flour into a large zipper bag...add the shallot rounds to the bag and give it a good shake, then place in a strainer and shake off any excess flour. fry the shallots in the hot oil in small batches until golden brown, 3 to 5 minutes. drain on paper towels
top the green bean casserole with the fried shallots and serve.

total time: 45 min
yield: 6 to 8 serving

NOTES:

1. I did the initial cooking of the green beans longer than he suggests just because I really don't like them crunchy...I am one of those weirdos who would rather they be over done  

2. I was a bit scared of the cayenne (especially when I tasted the green bean mixture BEFORE baking...but the heat mellows during baking to where I noticed the flavor but not really the heat

3. just like I substituted greek yogurt for the sour cream..next time I make this I will substitute either half & half or regular milk (or possibly evaporated milk..for the thickness factor) for the heavy cream...between the yogurt and the flour (and the butter when you cook the mushrooms) I really don't think there will be any real difference flavor-wise...I'll make a note here when I do, to let y'all know how it goes

4. I made the green bean mixture the night before and kept it in the fridge till it was time to bake the next day...while it baked I fried the shallots - turns out I could have fried the shallots ahead as well...I had some leftover which I put in a sandwich bag in the fridge and I've been munchin' on them for days - YUM! (obviously if you make them ahead..put them on the casserole in the oven for a few minutes to warm them up) 

5. his recipe called for doing it on 450º for 15 minutes...but again not being a bajillionairre I don't have multiple ovens at my disposal..I needed to be cooking multiple things in the same oven so I did mine on 375...obviously they'll need to be in there a bit longer...I think mine took about 20-25 minutes (until it's bubbly and golden on top)