Chicken Parmesan grilled cheese sandwich

1 cup cooked shrimp (peeled and chopped)
1 cup crab meat (lump or imitation crab)
2 cups fresh spinach (chopped)
1 cup shredded Parmesan cheese
2 cloves garlic (minced)
1/2 teaspoon onion powder
1/2 teaspoon paprika
Salt and pepper to taste
Chopped fresh parsley (for garnish)
Optional Ingredients:
1/2 cup diced bell peppers (for added color and sweetness)
1/4 teaspoon crushed red pepper flakes (for heat)
Instructions