In a bowl, mix together all of your dry ingredients.

Cut your butter in rough slices about 1/8 inch thick and add them to the flour mixture. Stir a few times to coat the butter, then add your cold milk and stir again just until you get a very rough dough that you can form into a ball. (Alternatively you can use a food processor for this, just be careful not to over-mix if doing it this way).

Wrap the dough and place it in the fridge for 30min to chill.

Next on a coconut floured surface roll the dough out into a rectangle as best you can (it's okay if it's a bit rough the first time, just gently push in the edges if pieces separate - also see my tips on rolling the dough if it's dry or sticking).

Fold one side of the rectangle inward, then the other until the dough looks like this (see photo).

Turn the dough 90* and Roll the dough out into a rectangle again, pushing down the layers you just formed. Repeat this 4-5 times. As you go, the dough will begin to form a nicer looking rectangle and the butter will become streaky and less clumpy.

Fold once more and then wrap your dough and place it in the fridge to cool for another 30min.

During this time, you can prepare your onions for the filling. To do so, heat a small frying pan with the olive oil over low-medium heat. Add the onions, garlic powder, salt and pepper and sauté until translucent (~3-4min). Remove from the heat and add your balsamic vinegar and syrup. Return to the heat and sauté for 1 more minute, then set aside.

After your dough is done chilling, pre-heat your oven to 400*F.

Again on a well-floured surface, roll your dough out into a thick rectangle (it will be hard to get it very thin at this point) and cut the dough in half with a sharp knife. Wrap half the dough and place it back in the fridge.

Working with half the dough now, roll it out into a rough rectangle about 1/8th of an inch thick (see photos).

Grease a 12 muffin tin tray with oil or butter.

Use a large coffee mug or a circle cutter to cut pieces of dough to fit inside the muffin cups. Repeat this with the second half of the dough and re-roll scraps as needed to form more circles (I refrigerate my scraps in-between to prevent them from getting to warm).

Place the circle cut outs inside the muffin tins, pressing the dough into the bottom and partially up the sides (don't over-work the dough, they don't have to look perfect or cover the entire tin). Use a fork to poke a couple holes in the bottom of each piece of dough.

Next, sprinkle some goat cheese into each tartlet, add your caramelized onions next, then sprinkle pecans and a pinch of rosemary on top.

Bake for 20-25min or until tartlets are golden brown around the edges and pop out easily. (You might want to check at 18min if your oven bakes on the hotter side because my oven bakes slow!) Serve warm or cool and freeze in an airtight container between layers of wax paper and re-heat on a baking sheet at 400*F until warm. Enjoy!