Preheat the oven at 175°C/347°F.
Place the beet root cubes on a lined baking tin, rub with olive oil and roast for 30 minutes.
Remove from the oven and set aside to cool.
Place the roasted beets in a food processor and pulse two or three times - you need some texture for the burgers, so make sure you don't mash them completely.
Transfer the beets into a large bowl, add all the other ingredients and stir to combine. If the texture is too mushy add more bread crumbs until you obtain the desired consistency.
With slightly wet hands, shape the burgers and place them on a lined baking sheet.
Bake in the oven for 15 minutes on one side, then flip over and bake for 15 more minutes.
Place the sweet potato strips on a lined baking sheet, rub with olive oil, than sprinkle with cornmeal and toss to combine.
Bake for 25-30 minutes, or until golden brown. They will be ready in the same time with the burgers.
While the burgers are baking, prepare the dressing and the buns. Place all the ingredients in the food processor and process to obtain a creamy sauce.
For the buns
Mix the yeast with sugar and let dissolve in a small bowl with the filtered water for five minutes, to activate it.
In a large bowl mix the flours with salt and ground flax.
Transfer into the food processor bowl, add the olive oil, vegan milk and dry yeast mixture and process to obtain an elastic dough.
Grease the large bowl with olive oil and transfer the dough into the bowl.
Cover with a clean kitchen towel and let rise in a warm place for at least 30 minutes.
Heat the oven at 200°C/392°F.
Line a baking sheet with parchment paper. Shape the buns and line them on the sheet. Let rise for another 15 minutes.
Bake for 5 minutes, then reduce the temperature at 175°C/347°F and bake for 30 minutes.
Let cool completely before slicing.
*This is a vegan version. For the vegetarians – just replace the ground flax with one organic egg. You can use an egg white to brush the buns top and sprinkle with mixed seeds that will stick on the buns while baking.
Assemble the burgers immediately after removing from the oven.
Cut the bun in halves, spread bun bases with dressing, add the beet burger and sweet potato fries, top generously with avocado dressing, parsley and put on the bun top.