Get your prep done before you start cooking. Cut the chicken fillets lengthwise in two parts. Season both sides with pepper, paprika and ½ teaspoon salt.
Peel the sweet potato and cut into bite-sized pieces. Peel and dice the potatoes. Grate the ginger and garlic cloves.
Heat oil and butter over medium high in a large skillet. Add chicken fillets and cook 2-3 minutes per side. The cooking time can vary with the size of your chicken. Remove from skillet and place on a clean plate.
Add potatoes and sweet potato, cook for 2 minutes. Stir in garlic, ginger, turmeric, cumin, mustard seeds and the remaining salt. Cook for 3 minutes until fragrant.
Pour in chicken broth and bring to a boil. Add green chilis, cover and simmer for 10 minutes over medium low.
When ready, taste and adjust salt. Return chicken fillets to the skillet. Simmer for 2 minutes, until heated through. Finish off with cilantro. Serve with warm naan and a creamy cucumber salad. Enjoy!