Best Shawarma Sandwich made at home

Ingredients used:
4 Larg chicken breasts split in half
2 tbsp olive oil
1 tsp salt
1 tsp pepper
1 tbsp Aleppo pepper
(you can use pepper
of your choice)
1 tbsp minced garlic
pinch of cinnamon
1/2 tsp 7 spice
juice of one lemon
1/2 tsp cumin
one onion
1 tbsp paprika