Christmas Crab & Shrimp Cocktail with Roasted Red Pepper Aiolli

In a bowl, gently toss the diced avocado with 1 teaspoon of the lemon juice to prevent discoloration. Refrigerate until chilled, 30 minutes to 1 hour. In another bowl, combine the remaining lemon juice, mayonnaise, green onions, shallots, mustard, and salt. Gently fold in the crabmeat so as to not break the lumps. Adjust the seasonings to taste. Cover and refrigerate until ready to assemble. In the bottom of 4 or 6 tall martini glasses or small footed compotes or bowls, place the diced avocado. Top with a dollop of the red pepper aioli and arrange the crabmeat in the center of the sauce. Arrange the shrimp around the outside rims of the glasses or bowls, and top each serving of crabmeat with a heaping tablespoon of the tomatoes. Garnish with the chives and additional red pepper aioli, as desired, and French bread croutons. Serve immediately.

In a food processor, pulse the egg and vinegar for 10 seconds. Add the roasted pepper, garlic, parsley, salt, and cayenne and pulse until smooth. With the machine running, slowly add the olive oil and vegetable oil through the feed tube and continue to process until the mixture forms a thick emulsion. Adjust the seasoning, to taste. Transfer to a clean container, cover, and refrigerate until ready to use. (The mayonnaise will keep for up to 1 day.)