1. Place chicken thighs in batches in a large plastic bag (or between two sheets of plastic wrap) and pound with a meat mallet on both sides to make thinner. Even thickness and narrower ends will help to hold the roll together.
2. Preheat oven to 380F (190C).
3. Season one side of the chicken with salt, pepper, onion powder and garlic powder.
4. Line a baking sheet with foil. Arrange the chicken pieces on the prepared baking sheet to form a large rectangular (seasoned side down).
5. Drizzle with lemon juice, season with salt, pepper, onion powder, garlic powder and cumin.
6. In a small bowl, whisk together eggs and milk. Heat oil in a large skillet over medium-high heat. Add the egg mixture and cook the omelet for a couple of minutes on one side, then flip and cook for another minute.
7. Arrange omelet along the middle of the chicken rectangular, evenly distributing.
8. Roll up, enclosing omelet filling and using the foil to help you tighten the roll.
9. Gently twist foil on either side of the roll to create a seal.
Transfer to the oven and bake for 35-40 minutes.
10. Let cool, slice and serve.