We loved this sauce. We used real butter, but will probably try margarine another time just due to the cholesterol issue. Left out the coriander and scallions because I didn't have any on hand. Made the tuna in a cast iron pan on the cooktop. A definite keeper.
DH loved this sauce. I seared the tuna steaks in a cast iron skillet with oil. I used reduced fat margarine for the butter since it was all I had. Thanks this is a keeper!