Heat oven to 350F

Slice the tips off the end off the head of garlic, leaving the cloves all attached. Brush with olive oil and wrap loosely in foil.

Saute the onion and celery in the olive oil for a few minutes until translucent. Set aside to cool.

Put the rest of the meatloaf ingredients in a large mixing bowl, along with the sauteed veggies, breaking apart the meat as you put it in. Use your fingers to gently mix everything together, Make sure to get everything thoroughly combined without over-working the meat, which can make it tough.

Turn the meat out onto a parchment paper lined baking sheet and form it into a long even oval. Ina says to flatten the meat out first to get rid of any air pockets, and then bring it back together into a loaf shape. I like my meatloaves fairly wide and flat so the meat cooks evenly. Be aware that the mixture will feel VERY wet at this point. That's good, it will give you a moist tender result.

Bake for about 50 minutes or until a thermometer inserted in the center reads 155-160F. Roast the garlic packet alongside the meatloaf for the entire time.

Let the meatloaf rest under foil for 10 minutes before slicing. Meanwhile, make the gravy by melting the butter in a saucepan and adding the chicken stock. Squeeze out the garlic from each clove, and add to the pan. Mash the garlic with the back of your spoon as you stir. Let the gravy come up to a boil, reduce the heat, and let reduce a bit. I like to add the bouillon cube and a splash of Worcestershire sauce for more color and flavor, but that's optional.

To thicken the gravy just a bit, sprinkle on a little Wondra flour while stirring. Strain the gravy through a mesh strainer and serve with the meatloaf.