Melt butter in a pan and keep it aside.
In a bowl add lemon juice, pepper powder, garlic powder, red chilli flakes, basil and chopped coriander leaves.
Add the melted butter and mix well.
Marinate the fish pieces in the butter mixture. You can leave it from 30 minutes to overnight. It tastes good even if you cook it immediately.
In a grill pan or tawa cook the fish pieces along with e butter mixture. Cook for 7 minutes on medium flame on each side.
Turn and cook the other side. Once done remove and place the cooked fish pieces on a plate.
In the same pan add the butter for making the sauce. Be careful not to burn the butter.
Once butter is melted add minced garlic cloves, lemon juice and cook on low flame for 3 minutes.
Once the sauce thickens, add pepper powder and pour the sauce over the grilled fish pieces.
Garnish with coriander leaves.
Serve as such or with rice / rice of your choice.