Portuguese
Bacalhau com Natas
Broad flakes of salt cod, tender fried potatoes, and sweet onions baked in silky cream béchamel beneath a deeply golden crumb.
6 servings · 55 minutes prep · 70 minutes cook
Ingredients
Salt cod
- 1 1/4 lb, Thick-cut and bone-in
- At least 3 qt, plus more as needed, Fresh cold water for the initial soak, subsequent water changes, testing, and poaching
Potatoes and onion
- 2 lb
- 4 cups, Neutral oil such as sunflower or canola, for frying
- 3/4 tsp, Diamond Crystal; do not increase before tasting the desalinated cod
- 3 tbsp
- 2 medium onions, 14 oz prepared weight, Halved and thinly sliced
- 3 medium cloves, 1/2 oz, Minced
- 1 bay leaf
Cream béchamel
- 3 1/2 tbsp
- 1/3 cup plus 1 tbsp
- 2 1/2 cups, Warmed
- 1 cup, Warmed
- 1/4 tsp, Freshly grated
- 1/2 tsp, Freshly ground; freshly ground black pepper may be used instead
- 1 tsp, Fresh
Topping
- 1/4 cup
- 1 tbsp, Use unsalted butter
Directions
Desalt and prepare the cod
- Begin 36–48 hours before cooking. Rinse the dried salt cod under cold water to remove loose surface salt. Place it skin-side up in a {{tool:nonreactive-mixing-bowl}} and cover with at least 3 quarts of fresh cold water. Refrigerate throughout the soak, changing the water every 8–12 hours for a total of five or six changes.
- After 36 hours, use the {{tool:chef-knife}} and {{tool:cutting-board}} to cut a small piece from the thickest section and simmer it in unsalted cold water for 2 minutes. Taste it: the cod should remain distinctly seasoned but should not taste aggressively salty. If necessary, continue soaking for another 8–12 hours, then drain well in the {{tool:colander}}.
- Place the cod in a {{tool:large-saucepan}} and cover it by 1 inch with fresh cold water. Bring just to a bare simmer over medium heat without boiling. Reduce the heat to low and poach until the flesh separates easily into moist flakes, 6–10 minutes after the water begins to tremble. Transfer to a plate and cool until safe to handle.
- Remove and discard the skin and every bone. Separate the flesh into broad flakes rather than shredding it finely, then set aside.
Fry the potatoes
- Using the {{tool:chef-knife}} and {{tool:cutting-board}}, peel the yukon gold potatoes and cut them into 1/2-inch cubes. Rinse briefly under cold water to remove surface starch, then dry extremely well with clean towels; residual water will spit dangerously in hot oil.
- Pour the frying oil into the {{tool:deep-fry-pot}}, leaving several inches of headroom, and use the {{tool:deep-fry-thermometer}} to heat it to 325°F. Fry the potatoes in three or four batches, stirring occasionally, until tender and pale gold rather than crisp and dark, 5–7 minutes per batch. Keep the oil between 310°F and 330°F.
- Lift each batch with the {{tool:slotted-spoon}} onto a {{tool:wire-rack}} or paper towels to drain. While warm, season all the potatoes evenly with the kosher salt. Do not add more salt at this stage because the desalinated cod supplies most of the casserole's seasoning.
Cook the onions
- Heat the extra virgin olive oil in a {{tool:large-skillet}} over medium-low heat. Add the yellow onion and bay leaf and cook, stirring frequently, until the onions are completely soft, translucent, and sweet but not browned, 12–15 minutes.
- Add the garlic cloves and cook until fragrant, about 1 minute. Fold in the prepared cod and cook gently for 2 minutes, just long enough to mingle the flavors. Remove and discard the bay leaf, then take the skillet off the heat.
Make the cream béchamel
- Heat the {{tool:oven}} to 400°F with a rack in the center. Butter a {{tool:shallow-baking-dish}} with a capacity of 3 quarts.
- Melt the unsalted butter in a clean {{tool:large-saucepan}} over medium-low heat. Add the all purpose flour and whisk continuously with the {{tool:whisk}} for 2 minutes; the roux should foam and lose its raw-flour smell without taking on color.
- Gradually whisk in the warm whole milk, beginning with a small amount and whisking smooth before each addition. Add the warm heavy cream, whole nutmeg, and white pepper. Bring to a gentle simmer and cook, whisking frequently, until the sauce lightly coats a spoon but still pours freely, 3–5 minutes. Keep it looser than a finished serving béchamel because the potatoes will absorb moisture in the oven.
- Remove the sauce from the heat and stir in the lemon juice. Taste the sauce together with a flake of cod. It should seem lightly seasoned alone and balanced with the fish; do not add salt.
Assemble and bake
- In the {{tool:mixing-bowl}}, gently combine the fried potatoes with the cod and onion mixture. Pour in about two-thirds of the béchamel and fold with the {{tool:rubber-spatula}} only until evenly moistened, taking care not to crush the potatoes or cod. Transfer to the prepared baking dish and spread without compacting it.
- Pour the remaining béchamel evenly over the surface. Combine the fine dry breadcrumbs with the melted butter and scatter the mixture in a thin, even layer over the top.
- Using the {{tool:oven-mitts}}, place the dish in the oven and bake until the sauce bubbles visibly around the edges and the top is richly golden brown, 25–30 minutes. If the casserole is bubbling but still pale, broil it 6 inches from the heat for 1–3 minutes, watching continuously. The center should be creamy and cohesive when spooned, with distinct pieces of potato and cod rather than stiff or sliceable.
- Rest for 10 minutes before serving. The sauce will settle and thicken slightly while remaining creamy.
