Beet and fennel burgers on portobello buns

Serves 2 (makes approx 4 burgers)


  • 1/2 small-regular sized bulb fennel, trimmed and outer layer removed, cut into chunks
  • 1 small-regular sized beetroot, peeled and cut into chunks
  • 1/4 red onion, peeled and chopped
  • 50g ground almonds
  • 25g coconut flour
  • 3 tablespoons ground flaxseed
  • 25g walnuts
  • 1 teaspoon ground cumin
  • 1 teaspoon paprika
  • 1/2 teaspoon sea salt
  • Pinch black pepper
  • 1 egg, beaten

For the mushroom ‘buns’

  • 4 large portobello mushroom caps
  • Melted butter or olive oil
  • 2 teaspoons of fresh or dried thyme leaves
  • Generous handful of spinach leaves

For the avocado mash

  • 1 avocado
  • Pinch sea salt
  • Juice 1/2 lime (optional)


Preheat the oven to 200C/Gas 6 and line two baking trays with baking parchment.

Prepare the mushroom buns by lightly brushing with the melted butter or olive oil, then place them on one of the trays.

Put the fennel, beetroot and onion into a food processor and pulse until finely chopped. Add the ground almonds, coconut flour, ground flaxseed, walnuts, cumin, paprika, salt and pepper to the processor. Add the egg and process until fully combined.

Take tennis ball-sized pieces of the beet mixture and shape and flatten into burgers. Place them on the other lined baking tray and bake in the oven for 35 minutes. After about 15 mins put the mushrooms in the oven so they have 20 minutes to bake.

Meanwhile remove the flesh from the avocado and using the back of a fork mash together with a generous pinch of salt and lime juice (if using).

To assemble, remove the mushroom buns from the oven.  Sprinkle the thyme leaves evenly over the buns. Divide the avocado mash and then place a few spinach or other leaves on each. Finally place the burgers on top.

TIP: sweet potato wedges go really well with these, especially with a sprinkling of paprika.