1 lb salt cod
2 medium baking (Idaho) potatoes, peeled and cut into 4-6 chunks each
1 Tbsp minced onion
2 Tbsp minced flat-leaf parsley leaves
1 clove garlic, minced
Lots of fresh black pepper
2 large eggs, separated
1 Tbsp all-purpose flour
1 Tbsp kosher salt
1 cup plain dry bread crumbs
Vegetable or canola oil, for frying
1 cup mayonnaise
1/2 chipotle pepper in adobo sauce, minced, or 2-3 Tbsp of the adobo sauce
*Soak the salt cod in a bowl of cold water in the refrigerator for 48 hours, changing the water 5 or 6 times.
Drain the salt cod. Place in a small pot of cold water with 1 Tbsp white cider vinegar or rice vinegar. Bring to a low boil and cook for 15 minutes. Drain, and set aside until cool enough to handle. Then, pick the skin and bones from the fish, and add the fish to a large mixing bowl.
Bring a small pot of water to boil; add the potatoes and cook until tender, 15-20 minutes. Drain and cool slightly, then add to the mixing bowl along with onion, parsley, garlic, egg yolks, pepper, and flour. Mash all together with a masher or wooden spoon, and mix to combine.
In another large bowl, beat the egg whites with a whisk until stiff peaks are formed. Gently fold the egg whites into the cod mixture; try not to deflate the egg whites. Season with salt.
Place the bread crumbs in a bowl. Form the salt cod mixture into balls the size of a walnut, and gently coat with the bread crumbs. Place on a platter, and cover with plastic wrap. Refrigerate for 1 hour or more, until ready to cook. Don't skip this step; the bolinhos are delicate and need time to set, or they'll fall apart in the frying.
Make the dipping sauce by mixing together mayonnaise and adobo sauce (or minced chipotles) until you like the taste, mild or spicy. Place in a serving bowl, cover and refrigerate, for at least 1 hour or more (can be made a day or two ahead of time).
When you’re ready to cook, fill a very deep, heavy saucepan with 1-1/2 inches of oil. (At the same time, remove the bolinhos from the refrigerator.)
Set the heat under the pan to high, and heat the oil until it reaches 350F or until it shimmers. One good way to test the oil is to stand a bamboo chopstick vertically with the eating tip down in the oil; if small bubbles appear at the base, the oil is hot enough.
Carefully fry the balls a few at a time, turning them a bit to make sure they brown all over, for 4-5 minutes. Remove with a slotted spoon or spider, onto a plate covered with paper towels. If desired, sprinkle with coarse sea salt.