Cook the brown rice according to package directions, about twenty minutes, and drain. Brown rice is a slow carbohydrate that raises your blood sugar gradually.
Heat half the olive oil in a frying pan. Sauté the finely chopped garlic briefly, add the halved cherry tomatoes and cook for a few minutes. Stir in the spinach until it wilts and season with salt and pepper.
Pat the cod dry and season with salt and pepper. Heat the remaining oil in a separate pan and cook the fish for about three minutes per side until it is opaque and flakes easily. Drizzle with lemon juice and serve on the vegetables with the rice on the side.