Step 1

Preheat oven to 180°C. Line a baking tray with baking paper. Toss pumpkin, fennel seeds and oil in a bowl. Spread evenly over tray.

Step 2

Add 1/2 cup (125ml) water and cover with foil. Bake for 40 minutes, then remove foil and increase heat to 220°C.

Step 3

Cook for a further 15 minutes or until caramelised. Remove from oven and mash with a fork.

Step 4

Set aside to cool completely. Transfer to a large bowl and combine well with yeast, flour, 1 cup (250ml) water and 1 tsp salt.

Step 5

Cover with plastic wrap and chill overnight.

Step 6

For the butter, place cream and kefir in a bowl. Cover with plastic wrap and set aside overnight at room temperature to ferment.

Step 7

The next day, whisk cream in an electric mixer on medium speed until split. Reduce speed to low and whisk for a further 8 minutes or until buttermilk has split out and butter resembles popcorn.

Step 8

Strain in a colander, reserving buttermilk for another use (store buttermilk in the refrigerator for up to 2 weeks).

Step 9

Place the colander in the sink, then rinse butter with iced water. Squeeze out excess liquid with your hands. Spread out butter and sprinkle with tarragon and 1 tsp salt. Form into a ball. Wrap in baking paper, then enclose in foil and plastic wrap. Store in the fridge for up to 3 months.

Step 10

Preheat a 3L-capacity cast iron casserole with the lid in a 220°C oven for 30 minutes.

Step 11

Turn out dough onto a work surface dusted with 1/2 cup (90g) semolina. Form into a ball. Carefully place dough into preheated saucepan. Dust with remaining

Step 12

1/2 cup (90g) semolina and score top with a sharp knife. Cover with lid and bake for 1 hour, then remove lid and reduce heat to 200°C.

Step 13

Bake for a further 15 minutes or until golden. Cool for 15 minutes in pan, then remove and cool for a further 10 minutes. Serve with cultured butter.