Preheat oven to 425 F.
Add butter (2 tablespoons) to a large heat-safe skillet, over medium heat.
Once melted, add sliced mushrooms (2 cups), yellow onions (1/2 chopped), salt (1/2 teaspoon), and pepper (1/4 teaspoon), and saute until soft - about 10 minutes.
Add heavy cream (1 cup), Tabasco (1/2 teaspoon) and thyme (1 teaspoon). Reduce the heat so the cream comes to a gentle simmer (high heat will ruin the cream). Cook veggies in cream until the cream has reduced by half, and the white sauce coats the back of your spoon - about 15 minutes.
Stir in shredded cabbage (2 cups), and cook in cream until wilted - about 5 minutes,
Remove skillet from heat, and add cheddar (1 cup), diced green beans (1 cup) and Albacore Tuna (3-5 Oz Cans drained ). Stir to incorporate.
Taste test to see if it's salted to your taste. I usually add an additional 1/2 teaspoon of salt here.
Sprinkle with the remaining cheddar (2 cups).
OPTIONAL (but adds a much-welcomed crunch! We always do this.): Place pork rinds in a sealed zip lock bag, and pound with a rolling pin, until the pork rinds are bread crumb sized. Sprinkle on top of your casserole.
Bake in preheated oven for 15 minutes, or until the cheese on top starts to bubble and the casserole is heated through.
Allow casserole to cool slightly before slicing, and enjoy!