Make the meringue by placing the egg white and cream of tartar into the Thermomix bowl, with the butterfly. Whip 4 min/37/speed 3.
Add sugar and salt slowly while whipping 3 min/50/speed 3. Set aside.
Combine Tequila, Cointreau lime juice, pineapple juice and ice in a cocktail shaker. Shake for 1 minute.
Put lime juice in a bowl and salt flakes in another bowl. Dip a glass in the juice, then the salt, to rim the glass.
Pour tequila mix in glasses, top with meringue, lime zest and a sprinkle of salt flakes
To make a mocktail, omit Tequila and Cointreau. Double the lime and pineapple juice. Add 3 drops of DoTerra Wild Orange Oil.