A member of the mackerel family, tuna are mainly found in the world’s warmer oceans. They can grow to a huge size (up to 700kg) and their meaty flesh is distinctively flaky and firm with a rich, strong flavour, the consequence of its comparatively high oil content. Tuna is mainly sold as steaks. It dries out quite quickly, so should be cooked very briefly over a high heat; marinated before cooking; or simmered in a sauce.
There are many different varieties of tuna but, largely as a consequence of prolonged overfishing, only a handful of these are commercially available – and most of those that are available are considered to be endangered to the point of extinction (Mediterranean and Atlantic) or in decline, particularly bluefin.
As tuna are oily, they go off quickly, so need to be very fresh. When buying tuna steaks, look for those that have been trimmed neatly, with firm, dense red or dark red flesh and a meaty aroma.
Avoid those with strong discolouration around the bone, or which have a dull, brownish cast. Thicker-cut steaks will stay juicier during the cooking process.
1/2 lb. Butter
1 tsp. Lime Zest
2 tsp. Lime Juice
1 Tbsp. Sage, minced
1/4 tsp. Salt
1 lb. Tuna
First lets start with the butter.
Butter and flavoring ingredients can be combined with a blender, food processor, or mixer. Using plastic wrap, the butter is rolled into a cylinder, chilled and sliced as needed. It’s as simple as that!
The zesty citrus from the lime counters the smooth flavor of the butter, while the sage lends a nice aroma to each bite. The craziest butter I ever made was a Pico de Gallo Compound Butter. I actually made salsa and blended it right into the butter.
I seared the tuna on each side and served it over sticky rice with broccoli. You can let the butter melt from the heat of the fish or help it along by sticking it briefly under the broil setting of your oven.
Rather than blending this butter, I softened it over very very low heat so the herbs could steep. Once it was softened, I incorporated the ingredients with a whisk and allowed it to cool. Once cool, I formed it into a cylinder using the method from above.