Spray a 6 qt or larger crock pot with a non stick cooking spray and turn to high.
Chop one onion into larger size chunks and place on bottom of crock pot.
In a large mixing bowl, mix ground beef, onions, eggs, mustard, milk, barbecue sauce, meat loaf mix, bread crumbs, garlic salt, pepper and red pepper flakes.
Once all ingredients are mixed together well, add mixed vegetables and then form into an oblong loaf placing on foil.
Roll edges up the sides of meatloaf and place into the crock pot.
Cook on high for 6 hours. Add additional barbecue sauce to the top of the meat loaf the last 1/2 hour of cooking.
Carefully remove meatloaf from the crock pot allowing the grease to drain into the crock pot.
Place on a serving tray and enjoy.
Adding potatoes, carrots and celery with the onions is how I usually make this meal.