Put the potatoes in the microwave to "bake" while the rest of your Pan Seared Tuna Steak dinner comes together.
Put a skillet on at low for the spinach with enough extra virgin olive oil to cover the bottom. Slice or coarsely chop up the garlic cloves and add them to the skillet. You are going to let the garlic just get translucent and not get brown. You are not going to add the spinach until the tuna steaks are done so if you need to turn off the heat on the garlic to keep it from browning, so be it. You can turn it back on just before you add the spinach.
Put the tuna steaks into a bowl and add the lime zest, lime juice, salt, pepper, dill weed and a splash of white wine. Or. you could just go with salt and pepper and squeeze some lime juice on them just before you dig in. That also works okay.
Gently turn them over a few tames to get them well covered with all of that good stuff.
Put a skillet on at medium high and add the olive oil and butter. When the butter has stopped foaming gently slip in the tuna steaks. The oil and butter will start foaming again but that's okay. Pour some of the lime juice mixture on them.
Assuming that your tuna steaks are 1" thick cook them for 1 and 1/2 minutes a side for rare. 2 and 1/2 minutes a side for well done. We like 2 minutes a side and medium rare. If in doubt just use a table fork to open a steak up a little and look at the inside to see how done it is.
Put the spinach in its skillet with the garlic and turn it over a few times as it wilts. When it is as wilted as much as YOU want it add it to the plates.
Now, serve up and enjoy your Pan Seared Tuna Steak with sautéed spinach and "baked" Potato.