In a large pan, saute cabbage noodles on medium with 1/2 TBS butter or coconut oil and tarragon (or other herb).
Saute until soft like a noodle.
Set aside.
To find out how much butter you will need for poaching the lobster, place the shelled lobster tails in a large pot, side by side; add just enough water to cover.
Remove the lobster tails and set aside; and measure the water in the pan. **NOTE: This is the amount of butter you will need in order to poach the tails.
Make sure to bring the lobster tails to room temperature before you begin.
To make the Beurre Monte, bring 1 tablespoon of water in a saucepan (which is large enough to fit the lobster) to a boil over high heat; reduce the heat to low and begin adding the chunks of butter (a little at a time) whisking to emulsify. Once the emulsion is started, you can safely add the butter faster without it breaking.
Hold the temperature of the Beurre Monte between 160 and 190 degrees for poaching.
If it gets too hot, the sauce will "break" but it will still taste good.
The mixture should have the consistency of a very thick butter sauce.
Use a thermometer and bring the beurre monte up to at least 160° degrees, but not over 190° degrees. Depending on how large your lobster is and how many you are preparing, will determine how long you need to poach them; about 5 to 7 minutes.
They should a soft consistency and look as if not completely cooked, if you over-do them, they will be rubbery. The lobster should be no longer opaque in color, but white when done.
Remove lobster from the Beaurre Monte and serve over Cabbage Pasta.