Cut the stems of the oyster mushrooms into about ½ inch thick medallions, depending on the size of your mushroom. Place in a bowl and cover with salted hot water and about 2 tablespoon of lemon juice.
While the stems soak, prepare your polenta. Bring the 4 cups of water and salt to a boil in a large pot. Once boiling, slowly add in your polenta in a steady stream while whisking constantly. Reduce heat to low and continue to whisk for a few minutes, until it is fully incorporated and begins to thicken. Cover until cooked, 15-20 minutes, checking every few minutes to stir.
When the polenta's texture is smooth, creamy, and thickened to your liking, stir in nutritional yeast and remove it from heat. Add in the chilled vegan butter. Stir until about half the butter is melted, then cover and set aside.
For the sun-dried tomato purée, simply blend the ingredients in a small blender, and if desired, add in more water until the desired consistency is reached.
Prepare the vegan scallops. Heat olive oil and butter in a pan over medium high heat. Drain the mushroom stems and add them to the pan along with garlic. Sauté stems for about 3 minutes on each side, until browned. Season with salt and pepper.
Once browned, remove the stems from heat and add the juice of half a lemon and parsley.
Assemble and serve! Place the scallops along with their sauce atop a bed of creamy polenta, and drizzle with sundried tomato purée. You can also serve it with wilted spinach (details in notes).** Enjoy!