In a small bowl mix all the glaze ingredient together; set aside.
Preheat oven to 350F with rack in the middle position.
Process crackers in a food processor until finely ground and place them in the bottom of a large bowl; stir in milk and set aside.
Place the onion and mushrooms in the now empty food processor and process until finely chopped.
Add the garlic and thyme to the onion and mushroom mixture. Using the oil in a 10-inch nonstick skillet over medium-high heat cook the mixture until moisture is evaporated and mixture starts to brown; set aside to cool for about 5 minutes.
Whisk the egg, mustard, mushroom mixture, salt, and pepper into the cracker mixture and then work in the meat using your hands. Form into 2 equally sized meatloaves and place them in the now empty skillet; bake for 20 minutes.
Remove meatloaf from the oven, spread the glaze over the tops, and continue baking until meatloaves are done. (160F)