For the crust, combine the flour, gum and salt togegther until well blended. Stir in the lime zest then cut in the butter until crumbly. Add in just enough lime juice until dough comes together.

To form tart shells, you can do them a few different ways: with a wooden tart tool, roll 1 tsp of the dough into a ball and place in well. Grease the end of the tart tool and press down while gently rock to form the shell. While this was the quickest method, it made the crust a bit thicker. Or roll dough out thinly and cut using a 3" circle, gently press into pan. Finally, you can take a teaspoon of dough, roll it into a ball and use your hands and fingers to flatten it into a circle. Any method will do, but the thinner the shell the better.

Place about 1 tsp of the prepared almond paste into each shell, or so until it's about 3/4 full. Do not overfill as they will rise in the oven.

Bake at 400°F for 15 minutes or until set and lightly golden.