Pesto & Mozzarella Portobello Burger
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Pesto & Mozzarella Portobello Burger

Pesto & Mozzarella Portobello Burger

with Balsamic Onion and Wedges

Our Pesto & Mozzarella Portobello Burger is a delicious veggie option that makes it easy to eat more veg in your diet and try something new!

Cereals containing gluten

Boxes and ingredients are packed in facilities that handles Peanut, Nuts, Sesame, Fish, Crustaceans, Milk, Egg, Mustard, Celery, Soya, Gluten and Sulphites. Due to the war in Ukraine, it has been necessary to substitute sunflower oil with rapeseed oil in some products without a label change. The FSA have advised that allergic reactions to rapeseed oil are rare.

Preparation Time35 minutes
Cooking time20 minutes


serving amount

450 grams


1 sachet(s)

Roasted Spice and Herb Blend

2 unit(s)

Portobello Mushrooms

1 unit(s)


1 ball(s)


(Contains Milk)

32 grams

Fresh Pesto

(Contains Milk)

12 milliliter(s)

Balsamic Vinegar

(Contains Sulphites)

2 unit(s)

Burger Buns

(Contains Cereals containing gluten May contain Milk, Egg, Soya)

30 grams

Onion Marmalade

Not included in your delivery

1 tsp


2 tbsp



Nutritional information

Energy (kJ)2936 kJ
Energy (kcal)702 kcal
Fat27.6 g
of which saturates8.2 g
Carbohydrate91.7 g
of which sugars19.8 g
Protein20.6 g
Salt1.46 g
Always refer to the product label for the most accurate ingredient and allergen information.


Baking Tray
Large Frying Pan
Medium Saucepan


Prep the Wedges

Preheat your oven to 220°C/200°C fan/gas mark 7.

Chop the potatoes into 2cm wide wedges (no need to peel).

Pop the wedges onto a large baking tray. Sprinkle over the roasted spice and herb blend. Drizzle with oil, season with salt and pepper, then toss to coat. Spread out in a single layer. TIP: Use two baking trays if necessary.

When the oven is hot, roast on the top shelf until golden, 25-35 mins. Turn halfway through.

Mushroom Time

Meanwhile, remove the stems from the portobello mushrooms (but leave the mushroom whole).

Heat a drizzle of oil in a large frying pan on high heat.

Once hot, fry the mushrooms until golden brown, 4-5 mins, then turn over and cook for a further 4-5 mins. Transfer them, stem-side up, to another baking tray.

Fry the Onion

While the mushrooms are frying, halve, peel and thinly slice the onion.

Heat a drizzle of oil in a medium saucepan on medium heat.

Once hot, add the onion, season with salt and pepper and fry, stirring occasionally, until golden, 10-12 mins.

Get Stuffing

While everything fries, drain the mozzarella and squeeze out as much liquid as you can. Pat dry with kitchen paper, then tear into small pieces.

Divide the mozzarella between the mushrooms. Drizzle over the pesto and season with salt and pepper.

Bake on the middle shelf of your oven until the cheese has melted, 8-10 mins.

Meanwhile, once the onions are golden, add the sugar (see pantry for amount) and balsamic vinegar. Cook until caramelised, 1-2 mins more.

Finishing Touches

Halve the burger buns. Pop onto the baking tray with the mushrooms and back into the oven to warm through, 2-3 mins.

Assemble and Serve

When everything's ready, carefully drain any excess liquid from the portobello mushrooms.

Spread the mayo over the bun bases and the onion marmalade over the bun lids. Top the bases with the stuffed mushrooms and the balsamic onions, then sandwich shut with the bun lids.

Serve the burgers with the wedges on the side.