Spring always reminds me of the diversity of kimchi. As some of my favourite produce comes into season, asparagus is easily at the top of the list, and turning it into a vibrant, tangy kimchi is a great way to extend its short season. All of the elements of the kimchi are then used in a tart: the brine is mixed into the cheesy base, which is then topped with the kimchi and finished with a final dollop of the kimchi paste to brighten the dish.

Asparagus kimchi

Keep in mind that the way you cut the asparagus will dictate the fermentation speed: smaller pieces will develop flavour much faster than whole spears. Taste the kimchi around the three- to five-day mark – once it hits that perfect tang, move it to the fridge for longer-term storage.

Prep 15 min
Cook 10 min
Ferment 3-5 days
Makes 150g

150g asparagus, woody ends removed
50g leek, trimmed, quartered and thinly sliced
50g apple, unpeeled and grated
5g minced ginger
5g minced garlic
10g gochugaru chilli flakes
15ml fish sauce (to make it vegetarian, use miso or doenjang instead)

Chop the asparagus into pieces the size of your choice. If you’re planning to make the asparagus kimchi tart below, I like to cut the spears into lengths roughly half the width of the pastry (ie, the size of each tart); otherwise, bite-sized pieces work well.

Put all the remaining ingredients in a large bowl and mix to the consistency of a rough paste. Fold the chopped asparagus into the paste (I generally use my hands to do this), applying pressure on the asparagus to facilitate the fermentation.

Decant into a clean container of your choice; I use a shallow glass one with a lid, in which the asparagus is snug and can lie flat, and all submerged in the other ingredients. Cover the entire surface of the vegetables with greaseproof paper or clingfilm (to minimise oxygen exposure), then seal.

Leave to ferment at room temperature for three to five days. During this time, you should notice water pooling at the bottom of the container. Once you’re happy with the flavour, move the container to the fridge for longer storage (that said, the texture will degrade with time).

Asparagus kimchi tart (pictured top)

This makes the best weeknight supper or springtime brunch. In theory, the tart will work with other types of kimchi, but always be mindful of the water content that’s released during cooking. My top tip? Saute the cabbage varieties of kimchi before using it for the tart.

Prep 15 min
Cook 25 min
Serves 4 as a starter, 2 as a main

320g sheet ready-rolled puff pastry
150g mascarpone
150g ricotta
1 egg yolk
½ tsp sesame oil
1-2 tsp kimchi brine (just the residual liquid brine, with no paste)
150g asparagus kimchi (see recipe above), plus residual kimchi paste to finish
30g grated parmesan
Egg wash
Chives, finely chopped, to garnish

Heat the oven to 220C (200C fan)/425F/gas 7 and line a baking tray with greaseproof paper. Unroll the pastry directly on to the tray, then cut it in half widthways to create two tarts. Lightly score a 2cm border all around the edge of each tart, then use a fork to prick holes all over the centre of the pastry.

In a bowl, whisk the mascarpone, ricotta, egg yolk, sesame oil and kimchi brine until smooth, then spread this evenly inside the borders of the pastry. Lay the asparagus kimchi on top, then sprinkle over the parmesan. Brush the egg wash over the exposed pastry border, then bake for 20-25 minutes, until the pastry is golden and slightly browned on top.

Remove from the oven, leave the tart to rest at room temperature for five minutes, then serve warm garnished with chives and generous dollops of the kimchi paste.

• Ferment: Simple Ferments and Pickles, and How to Eat Them, by Kenji Morimoto, is published by Pan Macmillan at £22. To order a copy for £19.80, visit the guardianbookshop.com