Kelp Lasagne: A Gluten-free Twist on A Classic

What if your lasagne sheets grew underwater?

Kelp’s broad, flexible fronds make a wonderful alternative to traditional pasta sheets. Layered with roasted vegetables, rich tomato sauce and creamy béchamel, they bring a subtle savoury flavour to this comforting classic.

Ingredients

For the kelp sheets

•⁠  ⁠200 g dried kelp, or enough fresh kelp fronds to make 8–10 lasagne-sized sheets
•⁠  ⁠Boiling water, for blanching
•⁠  ⁠Cold water, for cooling

For the vegetable filling

•⁠  ⁠1 aubergine, diced
•⁠  ⁠1 onion, sliced
•⁠  ⁠1 red pepper, sliced
•⁠  ⁠2 garlic cloves, finely chopped
•⁠  ⁠500 ml passata
•⁠  ⁠2 tbsp olive oil
•⁠  ⁠2 tbsp basil or pesto
•⁠  ⁠Salt and freshly ground black pepper, to taste

For the béchamel

•⁠  ⁠50 g butter
•⁠  ⁠50 g plain flour
•⁠  ⁠600 ml milk
•⁠  ⁠100 ml white wine, optional
•⁠  ⁠1 tsp mustard powder
•⁠  ⁠Salt and freshly ground black pepper, to taste

To finish

•⁠  ⁠50 g Parmesan, grated
•⁠  ⁠1 tsp paprika
•⁠  ⁠1 tsp Mediterranean herbs

Method

1.⁠ ⁠Prepare the kelp. If using dried kelp, rehydrate in water for 20 minutes. Rinse thoroughly, then place in a pan with enough boiling water to cover. Blanch for approximately 1–2 minutes for thin kelp, 3–4 minutes for medium-thick kelp or 5 minutes or longer for thicker pieces. Once tender but still slightly firm, transfer to cold water, drain and cut into lasagne-sized sheets.

2.⁠ ⁠Make the béchamel. Melt the butter, stir in the flour and cook gently for 1–2 minutes. Gradually whisk in the milk until smooth, adding the wine if using. Stir in the mustard powder and season.

3.⁠ ⁠Roast the vegetables. Toss the aubergine, onion and pepper with olive oil and seasoning. Roast at 200°C (180°C fan) for 30 minutes, stirring halfway through.

4.⁠ ⁠Make the filling. Gently fry the garlic in olive oil, then add the passata and basil or pesto. Stir through the roasted vegetables.

5.⁠ ⁠Assemble. Layer the vegetable filling, kelp sheets and béchamel in a greased ovenproof dish, finishing with béchamel. Sprinkle with Parmesan, paprika and Mediterranean herbs.

6.⁠ ⁠Bake. Cook for 25–30 minutes until golden and bubbling. Leave to rest briefly before serving.

A note on iodine

Kelp is naturally rich in iodine. Blanching in boiling water helps reduce its iodine content while softening the fronds, making them easier to use as lasagne sheets. The amount removed varies depending on the kelp and blanching time, so always follow the product’s recommended serving guidance.