1. In a saucepan of boiling water, cook the peas until tender, 3-4 minutes.  In th same saucepan, melt 1 Tbsp of the butter in the cream.  Add the peas and mash with a potato masher until chunky.  Season with salt and pepper and keep warm.

2.  In a small saucepan, simmer the wine with the lemon juice over moderate heat until reduced to 1 Tbsp, 8-10 minutes.  Reduce the heat to low and whisk in the remaining 6 Tbsp of butter,one Tbsp at a time, until the sauce is thickened.  Whisk in the tarragon and season with salt and pepper.  Transfer the sauce to a small bowl and keep warm.

3.  Heat a grill pan. Rub the salmon with the olive oil; season with salt and pepper.  Grill over moderate heat, turning once, until browned and just cooked through, 10-12 minutes.   Spoon the mashed peas onto a plate, top with piece of salmon and drizzle with sauce.