Finely chop onion, celery, carrot, garlic, and parsley. Trim and separate shimeji mushrooms.

Cut chicken thighs into large bite-sized pieces and season with salt and pepper.

Heat olive oil in a pot over low heat, add garlic, and sauté until fragrant. Add chicken, skin-side down, and cook until browned. Flip and cook for 2–3 minutes, then remove.

Add onion, celery, and carrot to the pot and sauté over low heat until the onion softens. Return chicken and add shimeji mushrooms.

Add canned tomatoes, white wine, and rosemary. Mix well, cover, and simmer over low heat for 15–20 minutes.