Dig out the core of the savoy cabbage carefully with a sharp knife, then pull off the leaves. Bring a large pot of water with some salt to a boil and boil the cabbage leaves for 5 minutes to soften, then cool off in a bowl of cold water to stop the cooking.
In a pan, cook the chopped onion in the olive oil for about 8 minutes, stirring frequently, until it starts to brown.
In a separate pot, cook the rice with the water by bringing it to a boil and then turning off the heat to let it sit and soak up the water.
In a medium bowl, mix the vegan ground meat, flax eggs, thyme, soy sauce, miso, salt and pepper, onions, and rice until well combined.
Take a leaf of softened cabbage and put a scoop (about 1/3 to 1/2 cup depending on the size of the cabbage leaf) of meat filling at the base of the leaf. Tuck in the sides and roll it up and away from you to form a neat little bundle.
Repeat until you run out of filling, arrange the cabbage rolls tightly in a casserole dish.
Blend the crushed tomatoes with the soaked cashews to create a smooth sauce.
Pour the tomato sauce over the whole casserole, covering all the cabbage rolls.
Cover with aluminum foil and bake at 400F for 30 minutes. Serve warm or freeze for future enjoyment!