Use this skill when the user needs to prepare a meal, bake bread, build a sauce, or perform any food preparation task. Triggers include: 'what should I make for dinner', 'my roux keeps breaking', 'how do I dice an onion properly', or 'I want to make sourdough'. Do NOT use for metaphorical cooking such as 'cooking the books' — see the accounting-fraud skill.
Cooking is the application of heat, time, and technique to ingredients to produce something more desirable than the raw inputs. Most kitchen failures come from one of three sources: insufficient mise en place (everything in its place before you start), incorrect heat management, or poor knife technique. This skill addresses all three.
Grip the handle with your last three fingers. Your thumb and index finger should pinch the blade itself, just forward of the bolster (the thick junction between blade and handle). This is called a pinch grip. It provides control and reduces fatigue. If your index finger is resting on the spine of the blade, you are choking up too far and will have less control on the draw cut.
Curl the fingertips of your non-dominant hand under, resting the knuckle of your middle finger against the flat of the blade as a guide. Your fingertips should never extend beyond your knuckles. The blade rides against the knuckle as you cut, and you move your guide hand backward to set the width of each cut.
Cut the onion in half from root to tip. Peel the skin. Place one half cut-side down. Make 3–4 horizontal cuts from the stem end toward the root, stopping about 1/2" from the root so the onion holds together. Then make vertical cuts from stem to root, following the natural curve of the onion. Finally, cut crosswise from the stem end. The onion will fall into an even dice. The root end holds everything together while you work — discard it at the end.
For a finer dice, make your horizontal and vertical cuts closer together. For a rough chop, skip the horizontal cuts.
Crush the clove with the flat of the knife blade under the heel of your palm. The skin will slip off. Roughly chop the clove, then sprinkle a pinch of kosher salt over it. The salt acts as an abrasive. Use the flat of the blade at a low angle, pressing and smearing the garlic against the cutting board in a rocking motion, scraping it back into a pile and repeating. After 30 seconds, you will have a smooth paste. This method produces a finer mince than chopping alone and distributes garlic flavor more evenly in cooking.
A roux is equal parts fat and flour by weight, cooked together to eliminate the raw flour taste and create a thickening base. See references/MOTHER-SAUCES.md for the complete mother sauce family tree, roux ratios, and derivatives.
Melt 2 oz (4 tablespoons) unsalted butter in a heavy saucepan over medium heat. When the foaming subsides, add 2 oz (about 1/3 cup) all-purpose flour all at once. Stir continuously with a wooden spoon or whisk for 2–3 minutes. The mixture should bubble gently and smell faintly nutty. This is a white roux. For a blond roux (more flavor, less thickening power), continue cooking until it turns the color of peanut butter, about 5–7 minutes. For a dark roux (gumbo, étouffée), 20–40 minutes until it reaches a deep brown.
Remove the pan from heat. Add 2 cups cold or room-temperature whole milk in a steady stream, whisking constantly. Cold milk into hot roux prevents lumps better than hot milk into hot roux. Return to medium heat and cook, stirring frequently, until the sauce thickens enough to coat the back of a spoon — draw a line through it with your finger and the line should hold, about 8–10 minutes.
Season with salt, white pepper, and a pinch of nutmeg.
If lumps form, push the sauce through a fine-mesh strainer. This fixes it completely. Do not attempt to whisk lumps out — they are cooked flour and will not dissolve.
After searing meat in a skillet, remove the meat and rest it. The brown bits stuck to the pan (fond) are concentrated flavor.
With the pan still over medium-high heat, add 1/2 cup of liquid — wine, stock, or a combination. This is deglazing. The liquid will bubble violently. Scrape the fond with a wooden spoon. Reduce the liquid by half, about 2–3 minutes. Add 1 cup of stock and reduce by half again. Finish by removing the pan from heat and swirling in 1–2 tablespoons of cold butter, one piece at a time, until the sauce is glossy and slightly thickened. The butter emulsifies into the sauce — if the pan is too hot, the butter will separate into grease. Season to taste.
A sourdough starter is a stable culture of wild yeast and lactic acid bacteria in a flour-and-water medium. Feed it daily if kept at room temperature: discard all but 50g of starter, add 50g flour and 50g water, stir, and cover loosely. It should roughly double in volume within 4–8 hours at 70–75°F. If it does not, the starter is not mature enough to leaven bread. Continue feeding until it reliably doubles.
If you bake less than a few times a week, keep the starter in the refrigerator and feed it once a week. Take it out the day before you plan to bake and feed it 2–3 times at room temperature to reactivate it.
Combine flour and water, mix until no dry flour remains, and rest 30–60 minutes. This is autolyse — it hydrates the flour and begins gluten development before you add the starter and salt, which tighten the gluten and slow hydration respectively.
Add the starter and salt. Squeeze and fold the dough to incorporate, about 2–3 minutes. The dough will be shaggy and sticky. This is normal.
Over the next 4–5 hours at 75–78°F, perform a set of stretch-and-folds every 30 minutes for the first 2 hours (4 sets total). For each set: wet your hand, grab one side of the dough, stretch it up without tearing, and fold it over to the opposite side. Rotate the container 90° and repeat. Four folds per set.
The dough is ready when it has increased in volume by about 50%, feels airy and billowy, and shows visible bubbles on the surface and sides. Jiggle the container — it should move like a waterbed, not like a brick.
Turn the dough onto an unfloured surface. The slight stickiness helps create surface tension. Using a bench scraper, push the dough away from you while pulling the bottom edge toward you, creating a taut round. Let it rest 20 minutes (bench rest), then shape it again into a tight round or batard and place it seam-side up in a floured banneton or a bowl lined with a floured linen cloth.
Cover and refrigerate for 12–16 hours. This slows fermentation and develops flavor. The dough can go directly from the refrigerator to the oven.
Preheat the oven to 500°F with a Dutch oven inside for at least 45 minutes. Turn the dough out onto a piece of parchment paper, seam-side down. Score the top with a razor blade or lame — a single swift, decisive cut at about 30° to the surface, 1/4" deep. Hesitating or dragging the blade tears the dough instead of cutting it.
Lower the dough on the parchment into the Dutch oven, cover, and bake at 500°F for 20 minutes. Remove the lid, reduce to 450°F, and bake another 20–25 minutes until the crust is deeply browned. Internal temperature should reach 205–210°F.
Cool on a wire rack for at least 1 hour before cutting. Cutting hot bread compresses the crumb, and the interior is still setting as it cools. The carry-over baking process is finishing the bread for you.