To start this comforting stew, we will need to cook the rice and lentils. This step can be done ahead of time or right before you begin the stew.
Rinse the lentils and add them to a pot with 3 cups of water. Bring to a gentle simmer and cook for 15 minutes. Add the rice to the same pot and continue simmering for another 20 minutes, until both the rice and lentils are tender. Set aside for later.
Heat a large pot on the stove over medium heat. Add 1–2 tablespoons of oil, followed by the onion, cabbage, and mushrooms. Cook, stirring occasionally, until the vegetables begin to soften and the onion turns translucent.
Add the garlic and chopped walnuts and sauté for another minute, just until fragrant.
Pour in the diced tomatoes, crushed tomatoes, vegetable stock, Worcestershire sauce, soy sauce, paprika, and thyme. Stir well, bring everything to a gentle simmer, cover, and let cook for about 30 minutes.
After 30 minutes, stir in the cooked rice and lentils. Cover again and simmer for another 15–30 minutes, depending on how tender you like your cabbage. We prefer it with a little bite, so 15–20 minutes is perfect.