Peal and finely slice the garlic, onion & celeriac. Clean then coarsely grate the courgette. Clean & thinly slice the mushrooms. Wash & drain the spinach.
Squirt the oil into a large heavy-based pan or casserole over a medium heat. Stir the garlic and onions onions to soften before adding the mushrooms. Allow them to sweat for a couple of minutes then stir in the curry powder.
Add the other ingredients apart from the spinach and bring to a simmer. Cover and cook for 10 minutes stirring occasionally.
Gently stir in the baby spinach, cover and cook for another minute or so to wilt. Season to taste and serve with rice or noodles.