Cut onion into bite-size pieces; heat 1 tbsp oil in a pot over med-high, then cook onions 5 min with salt/pep until softened

Add 2/3 cup sauce + ½ cup water to pot; bring to a simmer

Meanwhile, toast 1 ciabatta roll + slice in half; drizzle roll with 1 tbsp oil + salt/pep, then set aside

Cut cod into bite-size pieces + season with salt/pep; wash parsley, discard stems + chop; add cod, parsley + salt/pep to pot + cook 5-7 min until fish is cooked through; divide into 2 bowls + serve with toasty ciabatta on the side!