Preheat the oven for 350 degrees F.

To make the crab stuffing: Combine the crab, crackers, scallions, pepper, mayonnaise, egg, Worcestershire sauce, mustard, lemon, and garlic. Season the stuffing with salt and pepper and mix well. Set the stuffing aside.

Using a paring knife, slice the shrimp down the backs and remove and discard the 'veins'. Deepen the incisions if necessary, then spoon stuffing into each shrimp. Wrap each stuffed shrimp with bacon and arrange them in a large baking dish.

To make the pesto: pulse the basil, walnuts, cheese, and garlic together in a food processor (or grind in a mortar) then gradually incorporate the oil. Adjust the seasoning with lemon juice and set aside.

To make the roux: Heat the butter in a saucepan over medium heat. Add the flour, and cook, stirring, until the mixture, although still pale, looks dryer and no longer smells raw, about 5 minutes. Remove the roux from the heat.

Transfer the shrimp to the oven and roast until the bacon begins to render and brown, about 10 minutes. Flip the shrimp and roast on the second side until the shrimp are opaque, 5 to 10 minutes more.

Meanwhile make the lemon basil cream: Heat the oil and butter in a small skillet over medium heat. Add the onions and garlic and cook, stirring frequently, until the mixture is fragrant and golden, about 7 minutes. Add the wine and simmer for 5 minutes then add the cream. Simmer until the sauce has reduced by half. Add the lemon juice and pesto, then whisk in the roux a tablespoon at a time (use just enough to thicken the sauce). Keep the sauce warm over very low heat.

Arrange the shrimp on 4 warm plates and serve with lemon basil cream sauce on the side.

Cook's Note: It is difficult to make very small amounts of pesto and roux so we have prepared larger batches. The roux can be kept in the refrigerator and used to thicken soups, stews, and sauces. The pesto, which should also be refrigerated, is a delicious topping for pasta, a good sandwich spread, and nice addition to vegetable soup.