Chop and dry the vegetables: Place the carrot, celery, onions, parsley and garlic in a food processor and process until finely chopped (but don't turn it into a paste!). Place 1 teaspoon of olive oil in a skillet over medium-high heat. Add the processed vegetables and gently cook until dried out and starting to brown. Set aside to cool to room temperature.
Prep: At this point, preheat your oven to 350°F (175°C). Line a baking sheet with baking parchment.
Make the meatloaf mix: Place all remaining ingredients EXCEPT for the BBQ sauce into a large bowl. Add the cooled vegetable mix and, using a hand mixer with the hook attachment, mix thoroughly until the meat mix sticks together and all the vegetables are evenly distributed.
Shape and bake: Place the meat mix on the prepared baking sheet and shape into a loaf. Make sure you push it together into a firm loaf, otherwise it will fall apart. Brush with ⅓ of the BBQ sauce and bake for 30 minutes. Brush with another ⅓ of the BBQ sauce and finish baking for another 20-30 minutes, or until the internal temperature has reached 165°F. Immediately brush with the remaining BBQ sauce and allow to rest for 10 minutes before slicing to serve.