Preheat the oven to 375°F and grease a large dish (9x13) with nonstick spray, oil, or vegan butter.
Bring a large skillet to medium-high heat. Add the olive oil to it, then sauté the onions, peppers, and mushrooms until they start to soften (about 5-6 minutes).
Add the sausage to the pan and cook it for 1-2 minutes. Stir in the greens and take the pan off the heat once they have wilted.
Roll the crescent roll dough out onto the bottom of the dish. Press to seal any holes in the dough. Spread the sausage and veggie mixture out on top of it. Sprinkle most of the cheese on top.
In a large bowl, whisk the Just Egg, plant milk, salt, pepper, garlic powder, and paprika together. Pour the egg mixture all over the casserole layers. Spread the remaining cheese over the egg mixture.
Bake it in the oven for 40-50 minutes. Cover the dish if it looks like it might burn toward the end of the cooking time. Take it out when the top is starting to brown, and the middle stays firm when you give the dish a little shake.
Dust it with a fine layer of black salt and then let it cool for at least 10 minutes. Slice the casserole and enjoy!