Heat olive oil in a skillet over low heat. Add corned beef and onions and cook, stirring occasionally, until onion is translucent, 2 to 3 minutes.
Stir in eggs, and scramble until cooked, 2 to 3 minutes; don't overcook the eggs or they'll be rubbery.
Evenly portion out egg mixture over the bottom halves of the slider buns, add a piece of Swiss cheese, season with salt and pepper, and add the top halves of the buns. Serve warm.