Slice the baguette lengthwise, then into your desired lengths (see note)
Toss shrimp lightly in flour and set aside. In a sauté pan, heat butter and 2 tablespoons of the olive oil over high heat.
Sear shrimp until light pink, just a minute or two per side, and remove from the pan.
Add the last tablespoon of olive oil, and sauté the the shallot and garlic until lightly browned.
Deglaze the pan by adding wine and lifting any brown bits of the shallot and garlic that are stuck to the pan.
Add mustard, salt, cream, and lower the heat to medium. Simmer until the sauce is thickened, and will coat the shrimp nicely without running off (3-5 minutes).
Return the shrimp to the pan to re-warm. Toast the baguette slices in the toaster or a broiler for a few minutes.
Place the shrimp onto the toasted baguettes, sprinkle with the chopped basil, and serve.
Notes
You can serve this as a lunch or dinner on 6-inch baguette slices, where it goes nicely with a simple side salad. If serving as an appetizer, cut the baguette into 3-inch lengths.