Mean Meatloaf

Mean Meatloaf
adapted from Cook's Illustrated

3 ounces Monterey Jack cheese, grated on small holes of box grater (about 1 cup) (I used Mozzarella)
1 tablespoon unsalted butter
1 medium onion, chopped fine (about 1 cup)
1 medium rib celery, chopped fine (about ½ cup)
1 medium clove garlic, minced or pressed through a garlic press (about 1 teaspoon)
2 teaspoons minced fresh thyme leaves (I used 3/4 teaspoon dried thyme leaves)
1 teaspoon paprika
¼ cup tomato juice (I used fresh tomato juice I had in the freezer)
½ cup low-sodium chicken broth (I used my homemade chicken broth)
2 large eggs
½ teaspoon unflavored gelatin (powdered)
1 tablespoon soy sauce
1 teaspoon Dijon mustard
⅔ cup crushed saltine crackers
2 tablespoons minced fresh parsley leaves
¾ teaspoon table salt
½ teaspoon ground black pepper
1 pound ground sirloin
1 pound ground beef chuck