Heat the oil in a large soup pot. Cook the onion, carrots and celery for 5–7 minutes, until beginning to soften. Add the garlic and cook for 30 seconds.
Add the mushrooms and cook for 5–7 minutes, allowing their moisture to evaporate and the edges to brown.
Stir in the cumin, smoked paprika and thyme; cook for 30–60 seconds.
Add the lentils, barley, potatoes, broth, water, tomatoes, soy sauce and bay leaf. Bring to a boil, then reduce to a steady simmer.
Cook for 35–45 minutes, until the lentils are soft, the barley is pleasantly chewy and the potatoes are tender. Add water as needed.
Stir in the kale and cook for another 5–10 minutes. Remove the bay leaf, add lemon juice and season to taste.
A friendly note: These recipes are offered for general wellness inspiration. Individual nutrition needs and food restrictions vary; ask your healthcare professional for personalized guidance.