Chop the onions, carrots, and mushrooms into bite-sized pieces. Set them aside along with the plant-based beef substitute.
Heat the olive oil in a large pot over medium heat until warm and ready for cooking. Add the onions and garlic, cooking until fragrant and translucent, about 3–4 minutes.
Stir in the carrots and mushrooms. Cook for about 7–8 minutes, allowing the mushrooms to release their moisture and begin to brown.
Pour in the red wine, using a spoon to deglaze the pot by scraping up any browned bits from the bottom. Allow it to simmer for 2–3 minutes, letting it reduce slightly for enhanced flavor.
Stir in the tomato paste, soy sauce, vegetable broth, thyme, and bay leaves. Bring the mixture to a gentle boil.
Add your chosen plant-based beef substitute and stir it into the stew. Lower the heat and let it simmer uncovered for 25–30 minutes, stirring occasionally.
In a small bowl, mix the flour (or cornstarch) with a few tablespoons of water to create a slurry. Stir the slurry into the stew and cook for another 5–10 minutes, or until the sauce thickens.
Take out the bay leaves, then taste the dish and adjust the seasoning with salt and pepper to your preference. Garnish with fresh parsley before serving.