Mix together the breadcrumbs (3/4 cup), milk (1/2 cup), and grated onion (along with its juices) in a large bowl.
Add the egg, minced garlic, dried oregano (2 teaspoons), kosher salt (1 1/2 teaspoons), and black pepper (1/4 teaspoon) to the bowl and stir together.
Add the ground beef to the bowl and mix everything together, preferably using your hands (but if you're squeamish about touching raw meat, a spoon will work too).
Use a large disher scoop to scoop meatballs onto a rimmed baking sheet. Alternatively, you can use your hands to form the balls.
Mix the 4 tablespoons melted butter with the 2 tablespoons chopped fresh herbs in a small bowl.
Spoon the butter mixture evenly over the meatballs.
Bake at 375 degrees F for 30 minutes.
Serve, drizzled with butter and juices from the bottom of the pan.
This recipe made about 16 large meatballs. You can make them smaller and serve as an appetizer, if you prefer.
Make Ahead: Assemble these ahead of time on the baking sheet and keep them in the fridge for up to 2 days until you're ready to bake them.
Money Saving Tip: It's easy to make your own breadcrumbs from any leftover bread (I used hot dog rolls!) in your food processor! It's also cheaper to buy ground beef in bulk- just save what you don't use in the freezer for another recipe. You can also use 2 teaspoons dried herbs instead of fresh in the butter mixture.
Freeze 'em: Place the cooked meatballs on a baking sheet and freeze for 20 minutes. Then, move them to a plastic bag or airtight container to store for up to 3 months in the freezer. To defrost, microwave for a minute or two on 50% power.
The provided nutrition information does not include any added sodium from seasoning to taste, any optional ingredients, and it does not take brands into account. Feel free to calculate it yourself using this calculator or by adding the recipe to Yummly.