Chop the vegetables – Start by cutting all the vegetables into small cubes. Finely chop the onion and garlic, and roughly chop the walnuts.
Soften the onion – Heat a drizzle of olive oil in a large, deep skillet over medium-high heat. Add the chopped onion and sauté for about 2 minutes, stirring occasionally, until it starts to soften.
Add the zucchini – Add the diced zucchini and cook for another minute. Stir regularly so the vegetables cook evenly without browning too much.
Cook the root vegetables and add the TVP – Add the diced beet and carrot and cook for about 4 minutes, stirring occasionally, until they begin to soften. Add the TVP and chopped garlic and stir everything together.
Blend the tomato sauce – While the vegetables are cooking, add the tomato sauce ingredients to a blender (or immersion blender). Blend until smooth. If you don't have a blender, finely chop the canned tomatoes instead and add the remaining sauce ingredients directly to the skillet (when it's time).
Add the seasonings and mix well – Add the spices, walnuts and peas, cook for about 3 minutes, then add the boiling water and tomato sauce. Stir well to combine, cover, and cook for 5 minutes.
Cook the mince – Let the mixture cook covered for about 5 minutes, stirring occasionally. Add the boiling water and tomato sauce, stir well to combine, then cover the skillet and cook for another 5 minutes.
Add the remaining ingredients. Stir gently but thoroughly so the lentils remain mostly intact. Cover the skillet again and cook for another 5 minutes. Taste and adjust the seasoning if needed. The finished mixture should be thick, hearty, and moist but not watery.
Serve your way – Serve it with pasta or rice, use it as a filling for lasagna, spoon it into sloppy joes, or add it to tacos, burritos, pizza, or whatever meal you are craving.