Line a Baking Sheet with Aluminum Foil, extending it up the sides to catch grease. Optionally place a Wire Rack on top for better airflow and crispier bacon. Lay strips in a single layer — close but not overlapping. No oil or extra seasoning needed.

Set Oven to 400°F. You can start bacon in a cold oven as it preheats, or wait until fully preheated — both work. Use an external Meat Thermometer if your oven runs inaccurate. Start checking at 14–15 minutes. Thin-cut: 10–14 min. Standard-cut: 15–20 min. Thick-cut: 20–22 min. No need to flip. Check every couple of minutes after the first check — overdone happens fast. Pull bacon just before it looks done; it keeps cooking for a minute or two off the heat.

Peel and slice onions to about 1/8-inch thick — thin enough to cook quickly, thick enough to avoid scorching. Yellow or Spanish onions work best. Limit to 2 large onions per 12-inch Skillet to prevent steaming. Have your fat ready and keep a splash of water, broth, or wine nearby to deglaze if needed.

Heat a Skillet over medium to medium-high heat. Add butter, oil, or a mix and let it shimmer. Add sliced onions in large handfuls, stirring for 1–2 minutes per batch until they begin to soften — this prevents overcrowding. Once all onions are in, season with a pinch of salt. Cook over medium heat, stirring every few minutes, for 8–12 minutes total until soft, translucent, and lightly golden. To speed up softening, add 1/4 to ½ cup water or broth and cover; steam wilts the onions in a few minutes. Remove the lid once liquid evaporates and continue cooking uncovered. If the pan looks dry, deglaze with a splash of water, broth, or wine, scraping up any browned bits. Don't crank the heat — high heat burns the outside before the onions cook through.