Make the panade. Tear the bread into a large bowl and pour the milk over it. Let it sit for 5 minutes until the bread soaks up the milk, then mash it with a fork into a soft paste. This is the whole secret — soaked bread keeps the meatballs tender, where dry breadcrumbs would dry them out.

Mix gently. Add the ground beef, ground pork, Parmesan, parsley, eggs, garlic, salt, pepper, oregano, and red pepper flakes to the bowl with the panade. Mix with your hands just until everything is evenly combined — stop the moment it comes together. Overmixing is what packs the proteins tight and turns meatballs tough.

Shape them loosely. Wet your hands to keep the mix from sticking, and roll it into balls about 1½ to 2 inches across (a little bigger than a golf ball). Roll each one just enough to hold together — don't compress or pack them. You'll get about 24. Loosely shaped means tender.

Brown them. Heat the olive oil in a large skillet over medium-high. Brown the meatballs on all sides, turning gently, about 6 to 8 minutes total. They won't be cooked through yet — you're just building a flavorful crust. (Prefer hands-off? Bake them on a lined sheet pan at 400°F for 18 to 20 minutes instead.)

Finish in the sauce. Lower the browned meatballs into a pot of gently simmering marinara. Cover and simmer for 20 to 25 minutes, until cooked through (165°F inside) and tender. Simmering them in the sauce is what keeps them moist — and it gives the sauce a deep, meaty flavor you can't get any other way.

Serve. Spoon them over spaghetti with plenty of grated Parmesan, pile them on a roll for a meatball sub, or serve them straight from the pot alongside garlic bread. Leftovers are even better the next day.