Making the vinaigrette:
Combine the oils, vinegar, salt and pepper to taste in a sealable jar, cover, and shake until blended. Set aside.
Making the roulades:
In a small bowl, whisk together the mayonnaise and whiskey. Stir in the crabmeat and fennel seeds. Spread the crabmeat mixture onto the slices of salmon, roll up into cylinder shapes, and refrigerate for 15 minutes.
In order to prevent the avocado slices from going black, brush them with freshly squeezed lemon juice.
To serve, divide the mixed greens among four salad plates. Place two roulades and two slices of avocado on each, and sprinkle with the walnuts. Drizzle the vinaigrette over the greens. Serve immediately with brown soda bread.