Prepare the spinach mix by sauteing spinach leaves briefly until wilted. Set aside.
Cook chicken thighs in a skillet over medium heat until no longer pink, about 10-15 minutes. Shred the meat finely.
In a mixing bowl, combine softened cream cheese and shredded mozzarella cheese. Add shredded chicken, spinach, black pepper, and honey mustard. Mix well to combine.
Lay pastry sheet flat on a surface. Place about 2 tablespoons of the chicken mix onto the lower third of the sheet. Roll tightly like a spring roll.
Heat vegetable oil in a large pot to 375°F. Fry the rolls until golden brown, about 6-8 minutes.
Drain the rolls on paper towels and serve immediately with ranch dressing.
Notes
Feel free to modify the cheese type based on your preference. Opt for gluten-free pastry for a gluten-free version. Prepare filling the day before and fry when ready.