For the Bisque:

If your crock pot has a stovetop/sear setting, you can make this entire recipe in the crock pot. If not, start it in a skillet on the stove for steps 1-3 and transfer to the crock pot before step 4.

1. Set the crock pot to stovetop/sear setting (alternatively, heat a large skillet over medium-high heat on the stove). Add the oil and butter. Once the butter is melted, add the leeks, garlic, red pepper flakes, and a pinch of salt.
2. Cook for 5 minutes or until the leeks are tender. Stir in the tomato paste and cook for a minute or until it is melted and coating the leeks.
3. Pour in the wine and cook for a few minutes or until it is reduced by half. If using a skillet, it is at this point that you want to transfer the leek mixture to your crock pot. Be sure to get any residual juices in the skillet into the crock pot.
4. Add in the stock, tomatoes, Old Bay seasoning, and sugar, stirring well to combine.
5. In a mixing cup, whisk together the water and flour until smooth. Stir into the soup mixture. Add in the salt and pepper.
6. Cover the crock pot and set it on HIGH for 2 hours (or on LOW for 4 hours).
7. After it has cooked for the allotted time, taste the bisque base for seasoning and adjust as necessary. Stir in the shrimp, crab, cream, and parsley and continue cooking for another 15 minutes or until the shrimp are pink and cooked through. Keep warm until you are ready to serve.

For the Crab Salad Topping:

1. While the bisque is finishing up, make the crab topping by combining the lemon juice, mayo, mustards, and parsley in a mixing bowl.
2. Gently fold in the crab meat, being careful to not break it up too much. Season, to taste, with salt. Keep chilled until you are ready to serve.

To Serve:

Ladle the bisque into serving bowls and top with some of the cold crab salad. Garnish with additional parsley, if desired, and serve while hot with toasted bread or croutons.