Lightly season the cod with sea salt and let it rest for 15 minutes.
Slice the onion and crush the garlic.
Heat the olive oil in an oven-safe skillet over medium heat.
Cook the onion for about 5 minutes until softened.
Add the garlic and cook for another 2 minutes until fragrant.
Wipe away the excess salt from the cod.
Add the tomatoes to the skillet, then place the cod on top.
Season with black pepper and arrange the lemon slices over the fish.
Scatter the spinach, chickpeas, broth, and olives around the cod.
Bake the Baked Cod with Tomatoes in a preheated oven or air fryer at 180°C (350°F) for 15–20 minutes, depending on the thickness of the fish.
Add a splash of broth if the pan begins to dry out.
The cod is ready when it flakes easily and appears opaque.
Taste, adjust seasoning if needed, and serve with fresh lemon wedges.