Triple pork and spinach hero sandwich

Ingredients

• 1 tablespoon salt
• 1 tablespoon black pepper
• 1 teaspoon onion powder
• 1 teaspoon garlic powder
• 1 teaspoon paprika
• 1/2 teaspoon celery salt
• 1/2 teaspoon cayenne pepper powder
• 4 to 6 pounds pork roast or shoulder
• 3 tablespoons Dijon mustard
• 3/4 to 1 pound bacon
• 2 tablespoons bacon grease (reserved from cooking the bacon)
• 1 clove garlic minced
• 1 teaspoon sugar
• 2 tablespoons red wine vinegar
• pinch of salt
• small handful of baby spinach (stems removed)
• red onion, sliced and cut into small pieces
• 1 to 2 pieces of chopped bacon (cooked earlier)
• 1 six to eight inch bread roll, sliced
• mayonnaise and/or mustard
• slices of roast pork (from above)
• 2 to 3 slices of fresh mozzarella
• spinach salad with hot bacon dressing (from above)