Heat the butter in a pan on the stovetop over medium-low heat. Add the onions and cook, stirring occasionally, until they begin to caramelize. This takes about 20 minutes. (I will admit that I have skipped this step and just used raw onions when I didn't have time - it still turned out delicious!)
Take the onions off the heat and add the tomato paste, Worcestershire sauce, salt, mustard, pepper and garlic. Allow to cool slightly.
In a large bowl, lightly mix the beef, eggs, bread crumbs, pickled jalapenos, chopped bacon, and onion mixture. Mix just until incorporated.
If you're including veggies, toss them in a little melted butter and/or olive oil, plus salt, pepper and any other desired seasoning.
Form into eight individual loaves on your sheet pans or baking dishes, four loaves on each, equally spaced apart. Add your veggies in between the loaves on each pan so that they soak up the delicious juices from the meat.
Top each meatloaf with one tablespoon of ketchup. I don't usually measure the actual amount - I just eyeball it straight from the bottle, smoothing it with a spoon until the top is coated.
Bake for 40-45 minutes, or until the center reaches 165 degrees Fahrenheit.
Allow to cool for 5-10 minutes before serving.