Microwave butter and minced onion in a heatproof container for 2 minutes at 600W. Stir lightly and let cool. Drain canned corn using paper towels.

Combine breadcrumbs and milk in a bowl and let them soak.

Mix ground meat, cooled onion, salt, and pepper in the bowl until sticky. Add corn and mix evenly.

Divide the mixture into four portions and shape into oval patties, removing air pockets.

Heat salad oil in a frying pan over medium heat. Cook patties until browned on one side, flip, and cook for 1 minute. Cover and cook on low heat for 7 minutes until fully cooked.

Cool the patties completely. Wrap each patty individually in plastic wrap, place in a freezer bag, and seal with air removed. Label with date and freeze.