Preheat oven to 425°F (218°C).
Lightly grease the bottom and sides of a 9-inch cake pan with butter. Line the bottom with a parchment round. Set aside.
Line two baking sheets with parchment paper.
On a lightly floured work surface roll out puff pastry about ¼ to ⅛ inch thickness.
Using the 9-inch cake pan as a guide, cut out a circle that is an inch or so larger than the cake pan (10-inch round). Carefully move the puff pastry round onto one of the prepared baking sheets and with a fork, dock the surface. Cover with another piece of parchment, and place into the fridge to keep chilled until ready to use.
Slice carrots and parsnips lengthwise in half. If they are particularly thick, slice them lengthwise into quarters. To create a sunburst effect when arranging the root vegetables in the cake pan, slice carrots and parsnips into 4 to 4½-inch “sticks” in length.
In a large bowl combine the Redpath® Golden Yellow Sugar, melted butter, minced garlic, garam masala, and salt. Mix until thoroughly blended.
Add the root vegetables to the bowl, and toss to coat the carrots and parsnips with the brown sugar mixture.
Spread carrots and parsnips in a single layer, cut sides facing up onto the prepared baking sheet, scrape out any brown-sugar mixture and place onto the root vegetables.
Place into the preheated oven and bake for 10 minutes. Remove from the oven and with a pair of tongs, flip them over and bake for another 10 minutes until edges begin to caramelize; vegetables can still have a bit of crunch to them as they will cook for another 20 minutes or so when in the cake pan.
Remove from the oven and reduce oven temperature to 400°F (204°C).
Have at the ready the cold butter, lemon juice, salt, and garam masala. Place a medium, heavy-bottomed saucepan (see Chef’s Tips) over medium heat. Sprinkle in a quarter of the sugar and with a heatproof spatula move the sugar around to evenly heat the sugar. As it begins to melt and caramelize add another quarter of the sugar into the melted sugar. Repeat the process until all the sugar has been added to the saucepan. Cook the sugar until all the sugar is melted and has turned a deep amber colour. Do not leave it unattended as the sugar can quickly burn.
Remove pan from heat and immediately stir in the cold butter, lemon juice, salt, and garam masala. Adding the cold ingredients and liquid prevents the sugar from getting darker (see Chef’s Tips). Be careful as the caramel will steam and bubble vigorously. Keep stirring until the bubbling has died down and the butter is fully incorporated into the sauce.
Pour the caramel sauce into the bottom of the cake pan. Rotate the pan to coat the bottom. Let caramel cool for about 5 minutes before arranging the vegetables in the pan to prevent potential burns.
Arrange the roasted carrots, cut-side facing up, in a sunburst pattern over the caramel. Wherever possible point the “tips” or thinner parts of the root vegetables towards the centre of the pan. You may need to cut some of the carrots or parsnips into smaller pieces to fit them into the pan.
Once all the roasted vegetables are in the pan, remove the puff pastry round from the fridge. Place over the root vegetables and tuck the dough edges all around the vegetables.
Place into the preheated oven and bake until the pastry is a deep golden brown; 25 to 30 minutes.
Remove from the oven and place onto a wire cooling rack to cool for 30 minutes. Run a small offset spatula around the edge of the pan to help release the tarte tatin from the pan.
Place a dish that is slightly larger than the cake pan over the pan. With one hand on the bottom of the dish and one hand on the bottom of the cake pan, carefully and quickly flip the cake pan with the dish. Slowly remove the cake pan. Carefully peel away the parchment paper from the carrots and parsnips. Garnish with flaky salt and fresh mint if desired.