When doing the at home cooking as a single guy when you are trying to impress the ladies with out all the mess i feel it is about one aspect of the dish... for tuna it is all about the sauce so just keep a little special sauce in the back of the fridge for when the time is needed
asian goodness
9.3 oz (one bottle) Housin sauce (can be found in asian isle)
3 Tbls. Grated Fresh Ginger (got a sharp wood plainer it works great)
1 Tbls. Sambal (also in asian isle has a green top and is red sauce)

hot
1 Cup Rice Vinegar
1 cup Soy Sauce
2 tsp. Sesame oil
3/4 cup sugar
1/4 cup olive oil
1/4 cup water
put in a big boil and whisk well just add oils at the end while whisking. a lot of things you probably dont have in cabinet so when you go to make it just make a larger amount and store it can store for a month or so easily in air tight container.
now what to do with sauce...
while in asian isle grab some wonton wrappers or tortillas if you cant find wontons cut into triangles and fry in a little oil or bake to make crispy set aside... slice up (julienne) some peppers, onions, mushrooms saute in a large pan with a little oil until soft then add enough sauce to coat veggies and cook until becomes thick sticky... salt and pepper tuna and sear on high heat very quickly with a small amount of oil both sides you want rare (watch it carefully)... slice against the grains of the fish with a very sharp knife 1/4-1/2inch thick...
middle of large plate pile veggies place three fried triangles lean on all sides of pile place sliced tuna between triangles and drizzle a little sauce down each slice... if you have time and an asian market near you get some frozen seaweed salad thaw and put a pinch in the middle on top of everything