Heat a large saute pan or stock pot with a medium-high heat and add in a generous 2 tbsp extra virgin olive oil, after 1 minute add in ½ onion finely diced, 2 stalks celery roughly diced and 3 cloves garlic finely minced, mix with the olive oil
After about 3 minutes and the onions are translucent, add in 6 baby new potatoes (cut into quarters), ¼ tsp saffron threads and season with sea salt & black pepper, mix together until well combined, then add in 4 ¼ cups of fish broth and continue to cook on a medium-high heat
Meanwhile make the garlic aioli, add 3 cloves garlic finely minced into a mortar and a pinch of sea salt, pound down on the garlic until you form a paste, then add in 1 egg yolk at room temperature and ½ tsp lemon juice, start whisking all the ingredients together in a circular motion and at the same time slowly pour in ½ cup extra virgin olive oil, once all the olive oil has been incorporated and you end up with a thick and creamy mayonnaise like texture, the garlic aioli is done, set aside
About 15 minutes after adding the fish broth into the pan, the potatoes should be almost fully cooked, you can grab one of them and pierce with a toothpick, if it easily goes in but with some resistance, they are almost done, at this point add in a 14 oz filllet of cod that has been cut into 4 evenly sized pieces and seasoned with sea salt & black pepper, after 4 to 5 minutes remove the cod fillets from the pan and turn off the heat
To plate the fish stew, add in 1 slice of toasted bread into a shallow bowl, using a slotted spoon top off the bread with the potatoes and vegetables in the pan, add 2 cod fillets on top, pour in some of the hot broth all over bowl, add in a dollop of the garlic aioli and sprinkle with freshly chopped parsley, enjoy!