Heat olive oil in a large cast-iron skillet until shimmering. Add the shallots and a pinch of salt. Reduce the heat to low and sauté until the shallots are softened. Transfer the shallots to a bowl and set aside.
Melt the butter in the skillet and add the flour. Whisk to combine to form a roux. Slowly whisk in the milk until fully integrated into a smooth sauce. ** Simmer for a minute or two.
Stir in the shallots, mustard, and salt. Tear the Gorgonzola into chunks and add them to the sauce. Stir until the cheese melts completely.
Pour the gnocchi into the sauce and toss to coat. Bring back up to a simmer and let cook for 5-7 minutes or until the gnocchi is nice and fluffy. Take the skillet off of the heat and stir in the tarragon.
Spoon the gnocchi onto plates. Top with additional chunks of gorgonzola and drizzle with honey. Serve immediately.
