Make the cauliflower base: Combine the cauliflower, garlic, onion, bay leaves, water, and bouillon in a pot. Bring to a boil and simmer until the cauliflower is very tender. Remove the bay leaves and transfer the mixture to a blender. Add the plant butter (if using) and oat milk. Blend until completely smooth. Season with salt and pepper.

Roast the tofu: Heat the oven to 375°F. Toss the tofu with a little oil, salt, pepper, and poultry seasoning. Spread on a parchment-lined sheet pan and roast for 30 to 40 minutes, until lightly browned.

Cook the vegetables: In a large Dutch oven, warm a little oil (or use water). Add the onion and celery and cook until softened. Add the garlic and potatoes and cook briefly. Pour in the cauliflower base and bring to a gentle simmer.

Season and add the vegetables: Stir in the butter beans, frozen vegetables, poultry seasoning, granulated onion, turmeric, smoked paprika, and black pepper. Add the roasted tofu and adjust seasoning to taste.

Prepare a topping: For puff pastry: Place the sheet over the filling, score lightly, and brush with agave mixed with oil. For breadcrumbs: Toss the panko with nutritional yeast and oil. Toast in the oven for 5 minutes and scatter over the top.

Bake the pot pie: Transfer the pot or baking dish to the oven and bake at 375°F for about 30 minutes, until bubbling and golden on top. Allow to rest briefly before serving.