High Fibre Tacos: Non-fasting day recipe

  • Prep time:20 mins
  • Cook time:15 mins
  • Servings:4

This Carne Asada Tacos recipe is a great way to enjoy steak: it’s high in fibre, high in protein, and super high in flavour. The sumptuous steak’s versatility lends itself to be enjoyed as either tacos with wholemeal high fibre tacos, or on its own with no extras needed. This is a brilliant non-fasting day recipe for those following The New 5:2 or The Way of Life plans. On fasting days, simply remove the tortillas.

Sirloin steak, while it should be enjoyed in moderation, is rich in vitamins, minerals and protein. The protein in beef is known as ‘complete’ as it contains all the essential amino acids that humans need to get from food, as well as being essential for healthy weight loss, and for protecting you against a variety of chronic health conditions. This recipe contains a whopping 48.3g of protein, so if you’ve had a low-protein day you know that you’ll be covered if you whip this up as your evening meal.

This high fibre taco recipe also provides over a third of your recommended fibre intake, partly due to using wholemeal tortillas rather than corn tortillas. Wholemeal tortillas contain more health-protecting plant compounds than regular tortillas and, as this is what a healthy gut thrives on, this high fibre tacos recipe might be just what the doctor ordered. 

Another rich source of fibre in this super high fibre taco recipe are the deliciously hearty black beans. They’re a rich plant-based source of fibre, protein and various vitamins and minerals, and their high concentration of antioxidants help to protect the cells in your body, reducing the risk of conditions like cancer and heart disease. 

This recipe was developed by Karla at Mexican Food Memories, in collaboration with The Fast 800. Our shared goal is to bring you a variety of traditional Mexican recipes to try, all while applying Mediterranean-style principles, so you can enjoy lots of different flavours while keeping on track with your goals. 

So, what are you waiting for? Get that grill heated up!

Nutrition facts(per serving)


  • 600g sirloin steak
  • 2 avocado, sliced
  • 1 x 400g tin black beans (see notes)
  • 1/2 onion, finely chopped
  • 1 large tomato, finely diced
  • 12 small wholemeal tortillas
  • 4 tbsp chopped fresh coriander
  • 2 limes, plus extra for garnish
  • 4 tbsp extra virgin olive oil
  • Sea salt


  1. Open the avocado and use a spoon to scoop up the flesh and place it into a bowl. Mash it with a fork and add the onion, tomato, chopped coriander and lime juice to make a guacamole. Season with a pinch of sea salt. Mix well and set aside.
  2. Heat the black beans (in the microwave or in a pot) and season with a pinch of sea salt. Set aside.
  3. Preheat a grill or grill pan over medium-high heat. Rub the oil onto the steak and season with salt. 
  4. Place the steak on the grill and cook for about 4-6 minutes per side, or until cooked to your liking. Cooking time may vary depending on the thickness of the steak and your own preference. Once cooked, transfer the steak to a cutting board and let it rest for a few minutes. Then, slice the steak against the grain into thin strips.
  5. Serve the steak with your guacamole, warm beans, an extra wedge of lime and wholemeal tortillas - ready to make yourself some carne asada tacos!


  • Need it gluten free? Swap the wholemeal tortillas for the more traditional corn tortillas.
  • Spice this up with some diced pickled jalapenos.
  • Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat and serve.
  • The drained weights and calories of tinned ingredients will vary (sometimes significantly) from brand to brand. The drained weight of tinned black beans in four servings of this recipe equates to approx. 240g (8oz) and 260 calories.

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