Real Talk: You can’t use freshly cooked (meaning, still warm and moist) rice for this recipe. If you do, it will get gummy in the pan and won’t crisp. Day-old rice is ideal, or you can quickly dry out a just-made batch. Spread rice on a sheet tray and put in a low oven 5–10 minutes. Let air-dry for about 1 hour and up to 5. Seems nitpicky, but worth it!
Heat 1 Tbsp. oil in a medium nonstick or cast-iron skillet over high until oil shimmers and tiny wisps of smoke are visible. Cook pastrami, tossing often, until browned, about 2 minutes; transfer to a large bowl.
Heat 2 Tbsp. oil in same skillet over high and cook onion, stirring often, until translucent and just tender, about 3 minutes. Add sauerkraut, pickling liquid (stand back; it's going to bubble and splatter), ginger, and sambal oelek and cook, stirring occasionally, until liquid is evaporated, 1–2 minutes; season with salt and pepper. Transfer onion mixture to bowl with pastrami.
Heat 1 Tbsp. oil in same skillet over high and cook cashews, tossing often, until browned in spots, about 2 minutes; transfer to bowl with pastrami mixture.
Heat 2 Tbsp. oil in same skillet over high. Add half of beaten eggs and cook, stirring vigorously, 10 seconds (no, really, 10 seconds). Add half of rice, patting it down to an even layer and breaking up any clumps, then work out your frustrations and vigorously toss eggs and rice together. Continue patting and tossing until grains dry out, forming some crispy goodness, and separate, about 3 minutes; season with salt and pepper. Transfer to bowl with pastrami mixture. Repeat with remaining 2 Tbsp. oil, eggs, and rice. Transfer to bowl with pastrami mixture and toss to combine; season with salt and pepper.