Start by finely dicing your onion.
Add all the meatball ingredients to a large mixing bowl, except for the milk!
Add the milk to the mixing bowl, reserving about a third of the milk to add later.
Begin mixing together, adding a bit more milk at a time until it holds together, but isn't too wet to keep its shape. If it's still a bit dry and not sticking together, add more milk! While you've already added salt and pepper, we recommend frying a small piece of the mix before you form the meatballs to check for seasoning! You can also cook a piece of the mixture in the microwave to check for the seasoning. Add more salt and/or pepper if needed.
Form meatballs about 1 inch in diameter (we like to do this as we're adding them to a pre-heated pan, but it may be easier to do ahead of time!). Heat up a skillet or pan on medium heat.
Add oil or butter and place your meatballs in the pan, leaving at least an inch around all sides of the meatballs. You will likely have to fry these off in two or even three batches depending on the size of your pan.
Flip your meatballs once they have gotten a golden brown crust. Make sure to lower the heat if they start to brown too quickly. Cook until the meatballs are no longer pink in the center, or if you like to check the temperature, cook until they reach 160F on a thermometer. Continue with your second and/or third batch. (Note: if there's anything burnt to the bottom of the pan, we do recommend cleaning out your pan between batches to avoid any burnt/bitter taste on the meatballs)
Once you're done, set the meatballs aside and keep warm until ready to serve!
Optional (but highly recommended) step: Make a gravy! Start by melting butter over medium heat in a small saucepan. Once the butter has fully melted, add your flour and whisk to create a roux base.
Once the flour has toasted for about a minute, start adding your stock while whisking to dissolve the flour and butter. It may appear quite lumpy, but just keep whisking and they will disappear!
Add stock until you have reached your desired consistency, whisking constantly. A good measure of thickness is checking whether it coats the back of a spoon, and if you run your finger along the coating, it should leave a clear trail across the back of the spoon. Make sure the gravy comes to a boil to fully thicken. Season with salt and pepper to taste; we like to add a dash of nutmeg and allspice to the gravy for extra flavor!
Add in heavy cream and whisk to incorporate.
Transfer gravy to a serving container and keep warm until ready to serve!
Serve your meatballs with the gravy, mashed potatoes, and lingonberry jam for an IKEA style meal! You can also eat them by themselves, or with other vegetable side dishes!