These tarts were inspired by these blueberry and blackberry tarts by Ed Kimber (I seem to be taking inspiration from his bakes lately!). I came across the recipe one day and the image stayed with me: shades of blue rendered in differently shaped and textured berries. Here I’ve put the berry pairing over a posset, a sort of cooked and curdled citrus cream, which, despite how it might sound, makes for a delightful tart filling. The tarragon and lime in the posset are close to a lime-and-mint pairing: – fresh herbal and citrusy – but with an aniseed/liquorice-y vibe. If you like tarragon, this might be my new favourite tarragon pairing!
Okay, but I can’t just leave you with “posset is curdled cream” can I? While true, it doesn’t give posset nearly enough credit! Posset is sharp, sweet and like the smoothest, creamiest, richest pudding – think almost ganache-like in consistency. My mum used to make it to use up near-expired cream – and it is fast and simple as is her cooking style: just boil the cream with citrus juice and sugar, and it’s done. It would probably be one of my favourite things except that it is also very sweet. As the sugar content is something of a structural necessity (I think), I haven’t dared to tamper with it too much. Thus it works well here as a thin layer balanced with a fairly unsweetened tart crust and plenty of fresh berries.
Another great thing about posset – unlike a pastry cream filling, it won’t sog up your tart shells as quickly as pastry cream! While the posset can crack after a day or two as some of the moisture is absorbed into the tart shells, any surface cracks will be covered with berries, making it quite alright to make and fill the tarts a day or two ahead of time if needed.
tarragon lime posset tarts with black and blueberries
You will need five 9cm fluted tart tins (about 1.5cm tall). Posset adapted from Food52. Blueberry and blackberry arrangement based on these blueberry and blackberry tarts by the Boy Who Bakes.
- 56g softened butter
- 1/4 tsp kosher salt
- 1 tsp granulated sugar
- 25g egg, at room temperature
- 105g flour, half all-purpose and half whole wheat
- plus a bit of extra beaten egg
tarragon lime posset
- 240g heavy cream (36% milk fat)
- 2 large sprigs of tarragon (~3g)
- 60g granulated sugar
- pinch salt
- 1/4 tsp finely grated lime zest
- 37g freshly squeezed lime juice
- approx 250g blueberries
- approx 150g blackberries
- tarragon leaves
- finely grated lime zest
Cream the butter with the salt and sugar. Add the egg, a bit a time, beating in each addition completely before the next. Lastly add the flours all at once and mix in until combined. Pat into a disc, wrap in plastic, and chill the dough completely.
Remove from the dough from the fridge and place on a very lightly floured countertop (you may need to let the dough warm up on the counter for a few minutes first). Roll to about 2-3mm thick. Cut out at 12cm circles and use to line the fluted tart tins. In order to line all five tins, you’ll need to re-roll the scraps. This is a delicate pastry to work with, so don’t worry if it tears – just patch any tears together with a bit of extra dough.
Cover the tins and chill completely.
Preheat the oven to 375F. Dock the bottom of the tart shells with a fork. Bake until the tart shells are golden brown, about 20 minutes. Brush the shells lightly with a bit of extra beaten egg and return to the oven for another few minutes – this will help form a seal.
Let the tart shells cool completely. If there are any cracks, you can patch them with a bit of melted white chocolate.
tarragon lime posset
Heat the cream until steaming. Roll the tarragon between your fingers to bruise the leaves and help release the flavour, then stir into the hot cream. Cover and set aside to steep for at least a few hours or overnight (in the fridge).
Pass the cream through a sieve to remove the tarragon, pressing to extract as much cream as you can. Transfer the cream to a medium saucepan (we’re using a larger saucepan to prevent the cream from boiling over). Add the sugar, salt and lime zest. Bring the cream to a boil and let boil for 5 minutes, stirring occasionally. Remove from the heat and whisk in the lime juice. Transfer to a cup with a pouring spout and allow to cool slightly.
Keep the baked tart shells in their tins for extra support. Distribute the posset amongst the five tart shells. Tap lightly on the countertop if needed to level the surface. Place in the fridge and allow to set completely.
Place 4-5 blackberries (depending on size) on top of each tart. Fill in the spaces around the blackberries with blueberries and then pile on some additional blueberries to create a slightly mound of fruit. Scatter the tarts with tarragon leaves and finely grated lime zest.