The Irish Seaweed Christmas Kitchen – Seaweed Cookery Demonstration with Prannie Rhatigan

As part of the GENIALG Final Conference on 30 November 2020, we had a very special seaweed cookery demonstration with Irish seaweed expert Prannie Rhatigan. Prannie is also a public health doctor, so has been pretty busy these last few months as one of our frontline workers  so we were really delighted that she was able to find the time for some seaweed cooking too! In the demonstration, Prannie shows us how to cook four seasonal seaweed recipes: a root vegetable gratin with kelp centre, a winter solstice kale salad, a seaweed blend pesto and even a sea spaghetti chocolate Christmas tree! All the recipes were taken from her latest book, The Irish Seaweed Christmas Kitchen, which is available to buy here, you can read more about Prannie and the health benefits of seaweeds by visiting her website,


Why not try some more delicious seaweed recipes for yourself! Both Prannie’s cookbooks and other seaweed products are available to buy online from her Irish Seaweed Kitchen shop



Watch Prannie make seaweed seasonal with a root vegetable gratin with kelp centre, a winter solstice kale salad, a seaweed blend pesto and a sea spaghetti chocolate Christmas tree!


Root vegetable gratin with kelp centre

This looks like any other gratin until you start to serve it and the surprise layer of delicious umami kelp is revealed. The gratin can be prepared and left in the fridge overnight. 

Seaweed used: Kelp, dried seaweed blend

Serves: 6-8


  • 3 kelp pieces each approximately 11 inches (28cm) long, soaked in cold water for 30 minutes and simmered until soft
  • 1kg (2lb 2oz) mix of sweet potatoes, celeriac and parsnip, peeled and thinly sliced on a mandolin or by hand
  • 1-2 tablespoons dried seaweed blend

For garlic white sauce: 

  • 30g (1 1/4oz) butter
  • 30g (1 1/4oz) rice flour
  • 200ml (1/2 pint) milk, rice milk or milk of choice 
  • 3 garlic cloves, crushed
  • 1 shallot, finely chopped
  • 200ml (1/2 pint) milk or half milk and cream
  • 25g (1oz) parmesan cheese, grated


A gratin dish about 18 x 28cm (7 x 11 inches), well buttered.


  1. Preheat the oven to 160c/320F/Gas 3.
  2. In a small saucepan melt the butter. Make a roux by carefully mixing in the flour and gradually adding the milk. Cook until thickened slightly, adding more milk if necessary. Allow to cool and add garlic and shallot. 
  3. Place a layer of vegetables in the dis, slightly overlapping. Dot on around a quarter of the garlic sauce and sprinkle some seaweed blend. Repeat this step. 
  4. Place the kelp in a single layer as shown in the photo. 
  5. Continue to layer until all the vegetables, garlic white sauce and mixed seaweed are used up. 
  6. Sprinkle the top with parmesan cheese and carefully pour in the milk of choice or milk and cream. 
  7. Place into the oven at 160c (or leave in the fridge and cook the next day). 
  8. Bake for 1-1.5 hours until bubbling and tender. Allow to stand for at least 5 minutes before serving. 

Winter solstice kale salad

Seaweeds have been described as “the most nutritious form of vegetation on the planet”. Packed with minerals, vitamins and trace elements, they also contain useful lipids, phytodefensive components and antioxidants. They are powerhouses of nutrients and taste great.

A refreshing yet robust salad in the colours of Christmas with a surprising burst of sweetness.

Works well as a starter or side. 

Seaweed used: Dried seaweed blend

Serves: 4-6


  • 3 cups packed kale leaves, ribs removed, washed and torn into bitesize pieces
  • 2 tablespoons dried cranberries or 4 tablespoons fresh pomegranate seeds (or a half and half mix of both). Note: pomegranates are a healthier option as most dried cranberries contain added sugar
  • 2 tablespoons slivered/flaked almonds 


  • 3 tablespoons fresh lemon juice 
  • 3 tablespoons best quality olive oil 
  • 1 large clove of garlic, crushed
  • 1.5 tablespoons chopped mixed seaweeds
  • t tablespoon maple syrup 
  • 2 tablespoons dried chopped dates (or figs)


  1. In a small bowl, mix the marinade ingredients together. 
  2. Add the marinade to the prepared kale and combine so the leaves are well coated. Massage the dressing into the leaves with your fingers for a minute and then set aside to wilt and “cook”- allow 15 minutes at room temperature for curly kale to marinate and 30 minutes for cavolo nero kale. 
  3. Toast the almonds on a medium heat pan or under the grill for approximately 4 minutes in a pan or 3 minutes in a hot oven: be careful as they burn very quickly. 
  4. Toss in the cranberries/pomegranate mix and toasted almonds to the marinated kale, and serve. 

Seaweed blend pesto

We can all use a touch of magic in the kitchen, especially at Christmas. Add a dollop of pesto abd the transform the plainest store cupboard staples into snacks that can certainly go to the ball…

A magic wand in a jar.

Seaweed used: Dried seaweed blend 

Makes 5 servings 


  • 1 rounded tablespoon dried seaweed blend 
  • 5 tablespoons best quality olive oil 
  • 1/2 clove garlic, pressed


  1. Tip the seaweed into a small glass jar with a lid
  2. Add the olive oil and hint of garlic 
  3. Stir well and use at once or store in the fridge for up to a few days.

Serving suggestions: drizzle over rice cakes, baked sweet potatoes, roast vegetables, pasta, rice noodles, tofu, smoked salmon and cheeses. 

Sea spaghetti chocolate Christmas tree

Seaweed used: Sea spaghetti Himanthalia elongata


  • Chocolate
  • Sea spaghetti
  • Nuts of choice
  • Dried fruits
  • Berries
  • Cocoa powder for decoration 


Glass based dish, paper, pencil, ruler, greaseproof paper


  1. Start by drawing 10 crosses ranging from 19cm to 2cm sizes on paper
  2. Melt the chocolate in a bowl over a saucepan of boiling water
  3. Rehydrate the sea spaghetti by steaming it  
  4. Chop the sea spaghetti up into small bitesize pieces
  5. Add nuts, fruits, berries and chopped sea spaghetti to the melted chocolate and mix well
  6. Turn a glass based dish upside-down over the sheet of paper with the 19cm cross template, cover the 19cm template underneath with your chocolate mixture onto the glass. Decorate with nuts, fruits and berries
  7. Continue to make the rest of the nine crosses using greaseproof paper over the cross templates and refrigerate before assembly
  8. Glue branches together using more melted chocolate. 
  9. Dust with cocoa powder to give your tree a perfect snowy feel!