Rhubarb and Potato Gratin

This is adapted from the original Polish recipe for rhubarb and potatoes in two important ways: one is the addition of the breadcrumb topping which, frankly, just makes it an altogether more pleasant looking dish to serve up; the other is that I have reduced the amount of rhubarb by half.

The resulting dish has (to my mind) a pleasant tang, as opposed to a more pronounced tartness (though you can experiment with adding more rhubarb if you like). Also, where the original recipe called for dried mushrooms, I have used dried porcini, which give a nice depth of flavour, though you can try this out with whatever dried mushrooms you can get.

You’re also probably wondering (as was I when I tried the original recipe) about what exactly you would eat this with. While you could certainly scoff a portion of this on its own, I think pork, and particularly pork sausages, would make a very good accompaniment.

For the broth:

600ml water
6 dried porcini mushrooms (about 12g), roughly chopped, or substitute other dried mushrooms
1 medium onion, about 150g, sliced
2 bay leaves
4 x 10cm sprigs of dill
0.5 tsp salt
freshly ground black pepper

For the topping:

100g fresh breadcrumbs
2 tblsp butter
3 tblsp almonds, roughly chopped (optional)
coarse salt

For the rest of the sauce:

200g rhubarb, wiped clean and sliced into 2-3cm lengths
2 tblsp butter
2 tblsp plain flour
1 clove garlic, crushed
4 tsp chopped chives
500g boiled or steamed new potatoes (or any waxy potato), cut into chunks approx. 1-2cm thick

You’ll also need:

An ovenproof dish, one that’s around 18cm x 24cm and 4cm deep should do it.

The Steps:

To make the broth, add the water, dried mushrooms, onion, bay leaves, dill, salt and a few twists of black pepper to a heavy, medium-sized saucepan. Bring to a boil over a medium heat, then reduce the heat and simmer gently, covered, for about 30 minutes.
While the broth is simmering, you can prepare the topping. Start by heating a large frying pan over a medium heat. When hot, add 2 tblsp butter. Then add the breadcrumbs and almonds. Stir and fry for about 5 minutes or until the breadcrumbs start to turn golden, then remove from the heat. Sprinkle in a few flakes of coarse salt.
When the broth has finished simmering, add the rhubarb to the saucepan and simmer until tender and starting to disintegrate, about 15 minutes.
Remove from the heat and strain the liquid from the saucepan through a sieve into a bowl. At this point, what you have left in the sieve will have the appearance of a rather unattractive rhubarb mush and you may be tempted to turf it out but resist, it will be needed later.
Now preheat your oven to 180C.
Return your saucepan to a medium heat and add 2 tblsp butter. Allow the butter to melt and, as it starts to foam and bubble, stir continuously for around 6-7 minutes or until it turns a dark golden colour. It will have a butterscotch-like aroma.
Now make a roux by adding the flour to the butter and stir and cook for about 2 minutes. Then gradually add the strained rhubarb cooking liquid to the roux, stirring continuously until you have a smooth sauce.
Add the crushed garlic and chives to the sauce and season to taste.
Now add the reserved rhubarb mush to the sauce, along with the potato chunks. Remove from the heat and pour the contents into your ovenproof dish.
Sprinkle with the topping and bake for about 10 minutes. Serve hot, on its own or perhaps alongside some pork sausages.

The Variations:

I did tone down the rhubarb in this relative to the original recipe, but you can certainly try adding more rhubarb back in. You can also omit the breadcrumb topping if you like and instead just heat the final mixture through on the stovetop before serving.

The Results:

Side-dish servings for about 6 people or more substantial servings for around 4.