1) Bring a 4 litres of water to a boil in a stockpot. Salt it with 2 tablespoons sea salt. Wash the baby vegetables under cold water in colander.
2) Blanch vegetables in boiling water for 2 minutes, drain and refresh in cool water. Dry well.
3) In a large saute pan heat 1 tablespoon of butter with the garlic and saute until light brown. Add the cold water. When water comes to a simmer reduce heat to low and swirl in the butter, whisking constantly, one tablespoon at a time. When you add in the last of the butter also add the vegetables, tarragon, and pepper and just heat through. Taste and season with salt if needed. Remove from heat and serve.