If there's a tree-nut allergen concern here, we absolutely recommend using an alternate crust altogether. Never, never take a chance where food allergies are an issue. If that is the case, you can use a simple pie crust or pâte sablée, and carry on with the recipe as directed. If you just don't care for almonds, you can use cashews or pecans - but keep in mind that adding a different type of nut than the chef called for will change the overall flavor of your tart a bit. It'll still be delicious, though.