1. Combine the sour cream, mustard, scallions, lemon juice, Old Bay seasoning, Tabasco sauce, salt, and pepper in a medium mixing bowl and mix thoroughly.

3. Check the crabmeat for any small pieces of shell and discard them.

4. Gently add the crab to the mixture. Don’t over mix; you want the lumps of crab to remain intact.

5. Cover the mixture with plastic wrap and refrigerate for several hours so that the flavors meld.

6. Just before removing the mixture from the refrigerator, separate the English muffins into halves and place them on a baking sheet.

7. Remove the crab from the refrigerator and scoop equal portions on to each muffin half. Spread evenly.

8. Divide the cheese into four equal portions. Take half of each portion and sprinkle it evenly on the sandwiches. Set the remaining cheese aside.

9. Place the shrimp evenly on the tops of each sandwich.

10. Cover each with the remaining cheese and place them under the broiler for 2 to 3 minutes, until melted and bubbling.