Before beginning to prepare the casserole's filling, start off by boiling your pasta for what will be a total duration of roughly 7 minutes.

Heat a large saucepan over medium heat.

Add the onions and saute until they start showing signs of translucency.

Add the garlic and saute for a minute before adding the grated carrot, nori, ½ cup of diced oyster mushrooms, celery, and pimientos.

At roughly 2 minutes before the pasta is cooked, add the frozen peas.

Allow your vegetables to continue sauteing for 2 minutes, and then add the 2 cups of sliced oyster mushrooms and the riced cauliflower to your pan.

By now, the elbow macaroni should be al dente. Drain using a colander and set aside, reserving half a cup of water. Dissolve a vegetable bouillon cube in half a cup of pasta water.

Preheat your oven to 375°F

Pour in the almond milk, nutritional yeast, and dissolved vegetable bullion.

Mash the roasted chickpeas with a fork or process in a blender until lightly broken and add to your saucepan.

Turn up the heat and bring the mixture to a boil, stirring frequently.

Once it starts boiling, reduce the heat to low and simmer while infrequently stirring for 5 minutes.

Blend the cream of mushroom soup with eight tablespoons of water and then with three tablespoons of hot liquid from your pan and mix well before adding the soup into your casserole mixture.

Mix in the chopped parsley, black pepper, and season with salt according to taste.

Once the mixture has reached a thick consistency, combine it with the warm, drained elbow macaroni.

Pour the blend of pasta and sauce into an oiled casserole dish and top with panko breadcrumbs, grated vegan cheese, and sprinkle over the paprika.

Bake in an oven preheated to 375°F for 20 to 25 minutes or until the top turns golden brown.