Press the tofu: Wrap the block of 14 oz extra-firm tofu pressed and cut into 1-inch cubes in several layers of Paper Towel and set a heavy Skillet or 14 oz extra-firm tofu pressed and cut into 1-inch cubes press on top. Let it press for at least 15 minutes (or up to 30 minutes for maximum crispiness). Once pressed, cut the 14 oz extra-firm tofu pressed and cut into 1-inch cubes into 1-inch cubes.

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.

Air fry: Preheat your Air Fryer to 400°F for 3 minutes. Arrange the 14 oz extra-firm tofu pressed and cut into 1-inch cubes cubes in a single layer in the Air Fryer basket, making sure they are not touching. Air fry for 15–18 minutes, shaking the basket halfway through, until the 14 oz extra-firm tofu pressed and cut into 1-inch cubes is deeply golden and crispy on all sides.