Season chicken thighs with salt and optional pepper. Heat olive oil in a large pot over medium heat. Add chicken, skin side down, and cook until the skin is golden brown and crispy. Flip and cook the other side until browned. Remove and set aside.
In the same pot, add chopped onion, shiitake mushrooms, and celery. Sauté for about 5 minutes, stirring occasionally, until softened. Add garlic and cook for another minute until fragrant.
Pour in the chicken broth, bay leaves, thyme, rosemary, and carrots. Bring to a boil.
Lower the heat and return the chicken thighs to the pot. Simmer for about 30 minutes until the chicken is fully cooked and tender.
Add cauliflower rice, potato cubes, and kale to the stew. Continue simmering for another 10-15 minutes until the vegetables are tender.
Adjust seasoning with more salt, if needed. Remove from heat and discard the bay leaves.
Serve hot, garnished with fresh dill and lemon wedges for a fresh, herby finish.