Heat the olive oil in a large pot over medium heat. Add the sliced onion and minced garlic, then cook for 5 minutes until the onion softens.
Add the potato slices, crushed tomatoes, bay leaves, and smoked paprika to the pot. Stir to combine, then pour in 1 cup of water. Bring the mixture to a simmer, cover, and cook for 15 minutes until the potatoes are nearly tender.
Season the cod pieces with salt and black pepper. Place them into the pot and gently press them down into the liquid. Cover and simmer for 8 to 10 minutes until the cod flakes easily with a fork.
Remove the bay leaves. Taste and adjust salt and pepper if needed. Sprinkle the chopped parsley over the top before serving.