In a large pot or large dutch oven, heat olive oil over medium heat. Add the chopped onion and garlic, sautéing until softened, ~ 4 minutes.
1 tablespoon olive oil, 1 large onion, 3 cloves garlic
Add the sliced cremini mushrooms to the pot. Stir occasionally. Cook until the mushrooms release their moisture and start to brown, ~5 minutes.
1 pound cremini mushrooms, sliced
Add in the diced carrots, potatoes and rinsed lentils. Sprinkle the flour over the vegetables and lentils, and stir to coat. Gradually pour in the vegetable broth, stirring continuously to avoid lumps. If using wine, add it now. Bring the mixture to a simmer.
2 large carrots, 1 cup yellow or white potatoes, 1 cup cup dry green or brown lentils, 1 tablespoon all purpose flour, 4 cups low-sodium vegetable broth, 1 cup dry white wine
Stir in the chopped sage, dried thyme, salt, and pepper.
2 sprigs fresh sage, 1 teaspoon dried thyme, ½ teaspoon salt, ¼ teaspoon pepper
Reduce the heat to low, cover the pot, and let the stew simmer for about 25-30 minutes, or until the lentils and vegetables are tender.
Stir in chopped kale and soy sauce. Let it simmer for 1-2 more minutes and then its ready to serve.
1 heaping cup chopped kale, 1 tablespoon tamari or soy sauce
Optional: Squeeze some lemon on top. Serve the Sage and Mushroom Stew hot, garnished with extra fresh sage, with some freshly toasted bread.