Portobello steak, charred broccolini, mustard tarragon sauce

Portobello steak, charred broccolini, mustard tarragon sauce

This dressing is unequivocally mustardy: acidic, pungent, sharp, a tad bitter, subtly sweet, with tons of umami too. It is this savouriness in mustard that I did not appreciate before. It teases the palette and lingers.

I’ve prepared the giant portobello caps as ‘steaks’. Generally, I try and steer away from meaty terms to describe vegetables but here it feels like the most apt description. The mushrooms are dusted in cornflour (cornstarch), a coating that locks in moisture (and flavour), delivering a mushroom that is caramelized yet still juicy. Make sure you press and weigh the portobello down during cooking to get a nicely flattened ‘steak’ - I layered another skillet over the top. Something like this grill press would work well. Resting the portobello after cooking is essential. It allows the juices to settle and the mushroom to reabsorb them, giving you a juicy mushroom that is not soggy. This mirrors the technique of allowing meat to rest.

This mushroom dish is an elegant offering, a light meal that could be served as a starter. It can, of course, be easily transformed into a more substantial salad by adding brown rice, quinoa, farro or pearl barley.

Serves 4 / 
 vegan, gluten free

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Ingredients

• 450g / 1 pound broccolini, trimmed
• 4 large portobello mushrooms (about 575g / 20 ounces)
• extra virgin olive oil
• sea salt and black pepper
• 70g (1/2 cup) cornflour / cornstarch
• handful of tarragon leaves

Mustard tarragon sauce

• 4 tablespoons Dijon mustard
• 4 tablespoons tahini
• 2 small garlic cloves, grated
• 4 tablespoons extra virgin olive oil
• 2 tablespoons maple syrup
• 2 tablespoons white wine or champagne vinegar
• 2 tablespoons chopped tarragon
• sea salt and black pepper

1. Broccolini vary in length and thickness. Slice the stalks and flower diagonally into 5cm / 2-inch pieces; halve any stalks which may be extra thick. Set aside while you cook the mushrooms.

2. Remove the stem from the mushrooms and place them onto a tray or large plate, drizzle with olive oil and rub it all over the mushroom, making sure all the surface is coated. Season with salt and pepper and pat that into the surface. Scatter over the cornflour/cornstarch and coat the mushroom all over.

3. Heat a large frying pan (skillet) on medium high heat for 2 minutes. Drizzle with enough olive oil to cover the base of the pan (3-4 tablespoons). Add as many mushrooms as will fit, gill sides down, and place a heavy object such as another heatproof pan or a sturdy plate on top to squash and flatten the portobello (I used a similar sized cast iron pan and a lid to weigh it down further). Cook for 4 minutes. Remove the weights, - the bottom of the mushrooms should now be deeply caramelized - drizzle the top of the mushroom with some more olive oil and flip the mushrooms over. Cook for another 4 minutes, until the tops are deeply caramelized too. Transfer the mushrooms to a plate and allow it to rest. Continue cooking any remaining mushrooms.

4. When the mushrooms are done, drizzle more olive oil into the pan, and working in batches if needed, add the broccolini, season with salt and pepper and cook, tossing every minute or so, until the broccolini is charred in spots and just tender, 4 to 5 minutes (I like my broccolini crisp tender so if you prefer it to be softer, cook for an extra 1 to 2 minutes). Continue until all the broccolini is cooked and remove from the pan.

5. To make the sauce, combine the mustard, tahini, garlic, olive oil, maple syrup, vinegar and 1 tablespoon water into a small bowl and whisk to combine. If the sauce is too thick, add a splash or two more of water until the sauce is the consistency of thick cream. Add the tarragon and season well with salt and pepper. Whisk again until combined.

6. Slice each mushrooms into thin strips, keeping them close together to look like a ‘schnitzel’ - I like to do this on a diagonal, mainly for aesthetic reasons; you can slice your mushroom any way you like. Keeping slices together makes it easier to transfer.

7. Dollop or smear some mustard sauce on a plate, and using a fish or regular spatula, transfer one mushroom and place on top of the sauce. Place the broccoli around the mushroom, season with salt and pepper, and finish with a final drizzle of olive oil. Scatter with tarragon leave and serve.