Place potatoes in a medium saucepan; cover with water. Bring to a boil. Reduce heat. Simmer 20 minutes or until tender; drain. Cool. Combine potatoes and vinegar in a large bowl, tossing to coat. Add raisins, shallots, and tuna.
Combine mayonnaise and the next 5 ingredients (through pepper) in a bowl, stirring with a whisk. Add mayonnaise mixture to potato mixture; toss to coat. Chill 1 hour. Stir in almonds.