Fill a large pot with salted water and bring to a boil.

In a large non-stick pan, melt the butter over medium-high heat and sauté the shallots until slightly brown.

Sprinkle the shallots with flour and thoroughly mix. The flour will absorb all the butter. Pour in the cream and mix again.

Pour in the spinach and mix to wilt. Add the salt, crushed pink pepper, and tarragon. Reduce heat to medium-low.

Cook the linguine according to its package instructions.

Place the flounder fillets in the pan, delicately covering with the sauce. Cook for about 7 minutes or until the fillets flake easily with a fork.

Drain the pasta and serve the fish with the creamy spinach sauce.