Trim the stem end from the cabbage so it sits flat, then slice it into thin strips. Even slices cook more evenly, but there’s no need to be too precise.
Finely chop the onion and carrot and set them aside. They’ll form the base of flavor for the stir fry.
Warm the oil in a large skillet over medium heat. Once it’s hot, add the onion and let it cook until soft and fragrant. Stir in the carrot and continue cooking until everything begins to soften.
Add the mushrooms and give them time to cook down. They’ll release their moisture first, then start to brown and deepen in flavor.
Stir in the garlic and let it cook briefly until aromatic. Add the cabbage, cover the pan, and let it steam gently until it starts to soften. (about 6 min.)
Season with salt, black pepper, and paprika, stirring so everything is evenly coated. Add the tomato paste and cook a few more minutes, just until the flavors come together.
Finish with a sprinkle of fresh parsley and serve warm, either as a simple vegetarian main or as a side dish.