Combine ground veal, breadcrumbs, eggs, onion, garlic, jalapeno, Worcestershire sauce, tomato paste, salt and pepper in a large bowl.
Slice the poblano peppers open enough to allow meatloaf mixture tom be places inside. carefully remove the seeds. Tip: find how each pepper "stand" best to determine which side to slice open so each pepper will stand best on the grill and on the plate.
Chop the parts of the peppers cut off to add to your meatloaf mixture (you may not use all of it, depends on how much you have and how much you have and your taste for peppers)
Using your clean hands, gently mix the meatloaf mixture until combined. Season with additional salt and pepper if desired.
TIP: You can always quickly cook off a small "meatball" in a saute pan to taste your mixture and adjust seasoning or ingredients according to taste.
Stuff peppers with the meatloaf mixture. Stuff them full, allowing a mound of the mixture to rise from the opening. (the meat will shrink some as it cooks),
Heat grill to high and when ready place peppers directly onto the grates over direct heat and cook for 6-8 minutes. Then carefully move your peppers to indirect heat (turn the burner(s) off directly below them or move them to your upper grate) and continue cooking until done. I typically pull them when the internal temperature reaches 155 via digital thermometer, the internal temperature continues to rice after they are removed, hitting the recommended 160 degrees.
If choosing tom top with shredded cheese (a blend of cheddar and Monterrey Jack cheese is nice) do so a few minutes before the peppers are done to allow the cheese to melt. If brushing with barbecue sauce, do so a few times during the cooking process.