1/2 tsp. grated lemon zest
1/2 tsp. grated lime zest
2 tbsp. room temperature butter
1 1/2 lbs. salmon fillet
1/4 tsp. salt

Stir lemon and lime zests into the butter. Put the butter mixture on a piece of plastic wrap and roll to form a 1 inch cylinder. Either refrigerate or, if you're in a hurry, put in the freezer to firm while you cook the fish. Put the fish in a microwave-proof baking dish, thickest portion toward the edge of the dish. Pour in 1/3 cup water and sprinkle the fish with salt. Cover with plastic wrap and poke several holes in the plastic. Microwave on medium for 6 minutes and then turn the fish over and microwave 2 minutes longer. Top each portion with 2 thin slices of lemon lime butter and serve.

Calories, 292; protein, 33g; fat, 16g; sodium, 268mg; carbohydrate, .06g.