Marinate the chicken thighs:

1. In a bowl, pour in the vegetable oil, ketchup, and maple syrup. Add the chicken pieces and mix. Cover with plastic wrap and refrigerate for 2 hours.

2. Preheat the oven to 180°C/350°F.

3. Assemble the double skewers on wooden skewers previously soaked in warm water. This will prevent the wooden sticks from burning during baking.

4. Bake the skewers on a baking sheet for 8 to 10 minutes.