In a large bowl, using a hand beater, beat the egg whites, cream of tartar, salt and vanilla until soft peaks form. Gradually add the sugar and beat until the sugar dissolves and stiff peaks form, about 3 minutes. Gently fold in the chopped nuts.
Drop the batter onto silicone mats or parchment lined baking sheets (will need 2) with a teaspoon, spacing at least 2 inches apart. Bake until the meringues are dried through, about 2 to 2 1/2 hours. The cookies will remove easily from the parchment or silicone mat when ready.
Cook's Note: Do not bake on humid days. Dye these any color to suit a seasonal event. For orange cookies, add 5 drops of food coloring.