That’s a new one for me too. I can only imagine that it means to cook until the juices are gone and only fat remains to cook the meat. That would be well done... at least 165 degF. Might just be some old-school guidance or from someone who really follows FDA guidance.
Because it's Italian I don't think it has to do with FDA requirements. The word is "sfrigola" which apparently means "sizzle". I never understood whether "Until it sizzles" means you have to add the liquid immediately when it starts sizzling or if you're supposed to let it sizzle a bit so it browns, which then would make sense however due to the goal here to get a silky texture in the end product I would assume that one would not want to brown the meat.
Ahhh... bolognese... I may not be correct but this is what I do. For bolognese I cook until “just done” and immediately start building the sauce. Cooked with a hint of pink but no significant maillard. It tastes better to me that way.
For less refined sauces, or the American classic “Sloppy Joe”, etc... I cook off the water/juice until the ground meet fries to a brown crust in the fat. Then skim fat and proceed.
"Sfrigola" means sizzle. However, the recipe says "facendola rosolare finché non “sfrigola”." That means "making it brown until it sizzles." I take this to mean the meat should be heated until it just begins to sizzle but, not actually brown the meat. @brianshaw is correct.
For classic "sloppy joe" I use the leanest cut possible. I never use store bought ground as I always grind it myself fresh. That way I control the end product (not to mention the fresh aspect vs the unpleasant "surprise brown" section that plagues store ground meats. Here is the best "All American High School Cafeteria" version of Sloppy Joe I have found to date:
Great, thanks for the feedback all. What you describe Brian is pretty much what I do.
@mike9 funny one of the guests was so hungry while I was still building the lasagne he came into the kitchen with a piece of baguette and laddled some of the ragu bologna inside. I told him "in the U.S. we'd call that a sloppy joe".