Warm the milk until it feels warm (not hot). Stir in the yeast and let sit 5–10 minutes until slightly foamy.
In a large bowl, combine flour and salt. Pour in the yeast-milk mixture and olive oil. Mix until a shaggy dough forms.
Knead 8–10 minutes by hand (or 6–7 minutes with a mixer) until smooth and elastic. Cover and let rise until puffy, about 45–60 minutes.
Cook the chicken mince in a skillet over medium heat, breaking it up. Season with 1/2 tsp salt, 1/2 tsp black pepper, oregano, and Italian seasoning. Cook until no longer pink. Let cool slightly.
Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.
Punch down the dough and roll into a large rectangle on a lightly floured surface.
Spread tomato sauce over the dough. Sprinkle the cooked chicken and diced bell pepper evenly. Add most of the mozzarella, saving a little for topping.
Roll the dough into a tight log. Slice into 8 even spirals.
Arrange on the baking sheet. Cover and let puff 15–20 minutes. Sprinkle the tops with the remaining mozzarella.
Bake 15–20 minutes, until golden and baked through. Cool 5 minutes before serving.
