Boneless chicken thighs should be baked in a pre-heated, 425°F oven for approximately 20 minutes. Use a meat thermometer to check the internal temperature, and if necessary add extra time to ensure that the core temperature reaches 165°F to ensure safety.
It is advisable to season the thighs before baking. Seasoning choices often include a simple sprinkle of salt and black pepper, an Italian seasonings rub (such as oregano, basil and thyme) or a coating of a sauce (such as barbecue). Prior to seasoning, coat the chicken lightly in olive oil to aid in browning during baking.
A tangy glaze for boneless chicken thighs can be made with several tablespoons of olive oil, 1 tablespoon of balsamic vinegar, 1 teaspoon of brown sugar, 1 tablespoon of Dijon mustard, four garlic cloves and a pinch of red pepper flakes. An Asian-style sauce can be made with sesame oil and rice vinegar.
After the chicken has been oiled and glazed, it should go in an oven-safe dish that has not been greased. A 9 inch by 9 inch baking dish is typically an adequate size. If the chicken is not fully cooked within 20 minutes, continue to cook for increments of 5 minutes until done. Once removed from the oven, the chicken should sit under aluminum foil for 10 minutes before serving.