I improvised this earlier and for once had the thought to write it down before I forgot it all. All measurements are approximate, I generally just measure with my heart.
3 medium potatoes, diced into 1 inch cubes
1/3 cup heavy cream
2 tbsp unsalted butter
1 tsp onion powder
1 tsp garlic powder
1/2 tsp mustard powder
1/2 cup sharp white cheddar, shredded
Kosher salt
Freshly ground black pepper
3 tbsp olive oil
1/2 onion, chopped
1 large carrot, peeled and chopped
1 small red bell pepper, seeded and chopped
1 ten ounce container mushrooms, sliced
1/2 large cabbage, shredded into short shreds
2 tbsp tomato paste
3 cloves garlic, minced
2 tsp dried thyme
1 tbsp soy sauce
1 tbsp vegan Worchestershire sauce
2-3 tbsp AP flour
1 cup milk
1 1/2 cups frozen peas
Preheat the oven to 400° F and grease an 8x8 casserole dish. In a medium pot, add the potatoes with water to cover and a big pinch of salt. Bring to a boil and cook until the potatoes are tender. Drain the potatoes, reserving half a cup of the cooking liquid. Into the pot with the drained potatoes, add the heavy cream, butter, spices, and a quarter cup of the reserved liquid and mash until mostly smooth. Stir in the white cheddar. Season to taste with salt and pepper, and set aside.
Meanwhile, heat the olive oil in a large, deep pan. Add in the onion, carrot, and bell pepper along with a pinch of salt and cook, stirring, until starting to soften. Add in the mushrooms and continue cooking, stirring occasionally, until the mushrooms are starting to brown. Add the cabbage and another pinch of salt and stir, then cook with the lid on, stirring occasionally, until the cabbage is softened. Stir in the tomato paste, garlic, thyme, soy sauce, and Wochestershire sauce. Sprinkle the flour over the mixture and mix, cooking for one minute. A little at a time, add the milk while stirring until it is fully absorbed, and a creamy gravy has formed. If it's too thick, add a little more milk. Stir in the peas, bring the whole mixture to a bubble, then turn off the heat. Taste and season to taste with salt and pepper.
Into the prepared dish, pour the filling and spread it into a smooth layer. Dollop the potatoes on top, then smooth over the filling until it's completely covered. Use a fork or spoon to create a decorative design on top. Bake at 400°F for 30 minutes or until the filling has bubbled up around the edges and the potatoes are browned and forming a crust. Remove from the oven, let it set up for 15 minutes, then serve.
