Cook the brown rice for about twenty minutes in plenty of salted water until tender.
Heat half a tablespoon of olive oil in a pan and briefly sauté the minced garlic. Add the spinach and stir until it has wilted. Season with salt and pepper.
Season the cod fillet with salt and pepper. Heat the remaining olive oil in a separate pan and pan-fry the cod for about six minutes until cooked through, carefully turning it so it stays whole.
Spoon the rice and spinach onto a plate, place the cod on top and squeeze some lemon over it. Serve immediately.