Mash bread, milk, and egg into a paste. Let it fully hydrate, 5–10 minutes.
Sweat onion in olive oil with a pinch of salt until soft and slightly sweet. Add garlic, cook 30 seconds. Cool.
Into the panade goes: cooked onion & garlic, basil, oregano, tomato sauce, Worcestershire sauce, salt & pepper. Mix that first. Make it uniform.
Fold in beef and pork gently. Don’t knead like dough. Mix until just combined. Let it sit 10–15 minutes so the bread absorbs and the proteins relax.
Lay out two long sheets of plastic wrap. Form the meat into a log and roll it tight, like a giant sausage. Twist the ends to compress. Wrap that whole thing in foil.
Bake until the center hits 155°F. Rest it. Carryover will finish the job.
Warm extra tomato sauce with: butter, a touch of honey. Unwrap the loaf. Brush generously. Back into the oven, now on a rack, until sticky, shiny, browned.
Slice thick. More sauce if you want. Done.
Chill the whole loaf. Slice cold (it’ll be perfect). Sear in butter until crusty, then cover to steam through.