Start by cutting your white fish fillets into bite-sized pieces. In a mixing bowl, toss the fish with cornstarch (or flour), salt, and black pepper until evenly coated. Set aside for a few minutes.

Heat a large skillet over medium heat and add a combination of butter and olive oil. Once the butter melts and begins to bubble, carefully place the coated fish bites into the skillet. Sauté for 3-4 minutes on one side until golden brown, then flip with a spatula. Cook for another 3-4 minutes.

Remove the bites from the skillet and set aside. In the same skillet, add minced garlic and sauté for about 30 seconds until fragrant. Stir in lemon juice and zest, then return the fish bites to the pan for 1-2 minutes.

In a medium bowl, combine mayonnaise, minced garlic, a splash of lemon juice, and a pinch of salt. Whisk together until smooth and well blended.

Plate the crispy fish bites, garnish with freshly chopped parsley, and serve with the garlic aioli on the side.