Bring a large pot of salted water to a boil, then add the penne pasta. Cook for 8 minutes until al dente. Drain and rinse under cold water.

Heat 1 tablespoon of oil in a medium skillet. Sauté chopped onion and garlic until fragrant and translucent, about 3-4 minutes. Add ground chicken, paprika, allspice, cinnamon, and salt. Cook until the chicken is browned, approximately 5-7 minutes. Stir in the tomato paste and optional capsicum, cooking for an additional 2 minutes.

Melt 2 tablespoons of butter in a saucepan over medium heat. Whisk in ½ cup of all-purpose flour to create a roux, stirring for about 2 minutes until lightly golden. Gradually add ½ liter of lukewarm milk, whisking continuously for 5-7 minutes until thickened. Season with salt and black pepper.

In a large bowl, combine the cooked penne pasta with the chicken mixture. Preheat your oven to 220°C (428°F). In a baking dish, layer half of the pasta-chicken mixture and half of the bechamel sauce. Repeat layers and top with leftover bechamel, mozzarella cheese, and oregano.

Bake for 30 minutes or until the top is golden and bubbling. Broil for an additional 5 minutes for a crispy finish.

Allow to rest for 5 minutes before serving. Cut into squares and serve warm.