Preheat oven to 350 degrees. Grease or place paper liners in a muffin tin (paper liners make this super simple!).
Start with the lemon curd, as it will need time to chill (this can be done the night before). In a medium saucepan, combine maple syrup, lemon juice, lemon zest, egg yolks, and sea salt. Bring to a simmer over medium heat, whisking constantly until mixture starts to thicken, about 5 minutes.
With a fine sieve, strain into a bowl. Whisk in melted coconut oil.
Cover with plastic wrap, making sure wrap touches surface so a film does not form, and chill for at least an hour.
For the tartlet crust, in a medium bowl, whisk together almond meal, baking soda, and salt. Add melted coconut oil, maple syrup, and vanilla extract to mixture using a fork. Fold in thyme until evenly distributed.
Divide crust dough evenly in muffin tins, pressing firmly on bottom and up the sides about midway. Bake for 15 minutes or until crust starts to turn golden brown. Remove from oven and allow to cool in tin on rack for at least 10 minutes, then remove from tin and cool on rack for the remainder. If not assembling tartlets immediately, cover and place in fridge until you are ready.
To assemble tartlets, scoop lemon curd into crusts and garnish with thyme. Will keep in an airtight container in fridge for up to two days, but best served fresh.