Learning the best way to lock in the flavour of rhubarb from Iain Longhorn, and the perfect panna cotta to go with it

“A good panna cotta should be a miracle of cream, milk and prayers”
Ravinder Bhogal, chef-patron of Jikoni, in The Telegraph
One of the last social gatherings I enjoyed just days before the first lockdown hit was a cookery course run by Iain Longhorn at Hartnett Holder at Lime Wood down in the New Forest.
We were blissfully unaware of the approaching storm clouds, and just as well, it might have cast a shadow over the whole proceedings.
Instead, we were able to focus, carefree, on soaking up all Iain’s helpful tips and advice.
One technique which particularly impressed us was his method for macerating rhubarb. This was a revelation.
And he paired the rhubarb, not with the inevitable custard, but with panna cotta. Again, his panna cotta version was a triumph – not overly sweet since the condensed milk is tempered with buttermilk – and, although it incorporated gelatine, it didn’t set like concrete, so it still had a delightful coquetish wobble to it.
‘Why use condensed milk, why not just use sugar?’ one of us asked. The condensed milk gives a caramel taste, Iain told us… it’s richer and more complex. Announcing this dish to the Chief Taster later that evening, got, initially, a negative response, “I don’t like panna cotta”, but a few spoonfuls later the comment was, “I really like this.” A result then!
What’s the difference between forced rhubarb and normal rhubarb?
Forced rhubarb is grown is grown first outside for a couple of years so that its roots toughen up with the frosts. Then it is grown inside by candlelight with the roots warmed so that the stalks beging to grow and seek the light. It’s available from late December until late March. It’s more tender than ‘normal’ rhubarb. It’s sweeter and more delicately flavoured. The outside is blood-red whereas the inside is white.
Some of the best forced rhubarb available is Tomlinson rhubarb which has PDO status – bright pink and sweet, it’s grown in the famous west Yorkshire rhubarb triangle. You can get it in February from The Green Berry. For an interview with Rhubarb Rob of Tomlinson rhubarb on Saucy Dressings follow this link.
Making rhubarb even pinker
Alex Bond, chef at Alchemilla in Nottingham, suggests adding some dried hibiscus flowers whilst infusing to help retain the blushing pink colour. Take the flowers out for the stewing process, and add back in at the end as a garnish.
How to pickle rhubarb
To pickle rhubarb boil caster sugar with a Chardonnay or Muscatel vinegar, take off the heat, add diced rhubarb, and leave to macerate for 24 hours. Serve with goats cheese or mackerel fillets.
Various points about other things you can serve panna cotta with
You can serve panna cotta with other things – not just rhubarb.
It goes well topped with Rote Grütze, or flavoured with coffee in which case add a couple of tablespoons of strong espresso coffee, or one of those nespresso capsules.
Alternatively it is good served with honeycomb.
Or you can try topping it with a mango coulis. Go to Spoon Fork Bacon for some enticing photographs and their recipe. Or you can experiment with all sorts of other types of coulis.
Various points about the panna cotta
You will have some condensed milk left over, why not make these condensed milk cookies?
For more about cooking with gelatine, follow this link.
The panna cotta will keep for a week in the fridge (keep it separate from the fruit).
Various points about the recipe as a whole
- I’ve changed some of the measurements to streamline the process and reduce waste.
- Try a French Muscat or a Spanish Moscatel to go with this… or a Sauternes.
- Ben Tish, Chef Director at Cubitt House collection serves his panna cotta and roasted rhubarb with a little masala syrup.

Iain Longhorn-inspired macerated rhubarb with wobbly panna cotta
Serves – 4
Ingredients
- A few gratings of ginger
- Orange zest from half an orange
- 240 ml/1 cup double cream
- ½ a vanilla pod (or a teaspoon of vanilla paste)
- 120 ml/½ cup condensed milk
- 1½ gelatine leaves
- 600 ml/2½ cups buttermilk, made by adding a couple of tablespoons of lemon juice to that volume of full milk
- 4 stalks of rhubarb – about 200g/7 oz
- 50g/¼ cup golden caster sugar plus a tablespoon extra for the oats
- 2 tbsps oats
- pinch of salt
- touch of butter
Photos


Instructions
- Cut the rhubarb into 2”/5 cm lengths, and cut each of these pieces into quarters vertically. Put in a bowl, and add 50g/¼ golden caster sugar and the ginger and the orange zest and leave for as long as you can.
- Meanwhile, soak the gelatine in a little cold water to soften it.
- Put the cream into a small saucepan and slowly bring to the boil. Scrape the seeds from the pod into the cream (or the paste if you are using).
- Add the condensed milk, and bring up to the boil again.
- Take the saucepan off the heat. Pick the gelatine up out of the water and squeeze gently to get rid of the excess water. Add to the cream mixture. Stir well to ensure it dissolves and mixes through.
- Allow it to cool down, at least until you can easily touch the saucepan, or dip your finger in. You are about to add the buttermilk, and if the cream is too hot it will split.
- Add the buttermilk, and stir in thoroughly. Pour into four individual bowls and put into the fridge to set for about four hours.
- Put the rhubarb into a saucepan with a lid. Cook, covered, very gently for a maximum of ten minutes. Just as the lengths look as if they are beginning to soften, remove and allow to cool. Taste. If it is still a bit sour, and not soft enough to eat, cook for a bit longer, adding a little extra sugar if necessary.
- Fry the oats with just a tiny slick of butter, a little sugar and a pinch of salt.
- To serve spoon the macerated rhubarb over the panna cotta, and top with the toasted oats.

This post is dedicated to Alex Gamble.
For an interview with Iain Longhorn about setting up a cookery school, follow this link.