Peel the sweet potatoes and cut into small chunks, then boil them for around 20-30 minutes until cooked and soft. If the quinoa isn't already cooked, you can also boil and cook the quinoa now - this should take 15-20 minutes. Lastly, leaving the chickpeas in boiling hot water for 5 minutes will soften them so they are easier to mash (I just added them to the boiling sweet potato after around 15 minutes).
Once everything is boiled and soft, you can make the falafel balls. Start by heating the oil and grated garlic and ginger in a pan or wok. Let this cook on low heat for a minute and then add the quinoa, sweet potato pieces and chickpeas. Now add the salt, all the spices, rice vinegar and lime, and mash together. Taste and add more chilli, salt or lime to taste. Let this cool for 5-10 minutes, until you can touch and roll into balls. Make the balls by rolling together between the palms. Applying oil on the hands makes the rolling easier. Place the balls on a baking tray and leave them under the grill for around 10 minutes until slightly brown, turning them a couple of times. You can then also make these balls a little more crispy (optional) by stirring them in a pan - heat a little oil in a pan, add some cumin seeds and then let the falafel balls cook, shaking them in the pan so that they become lightly brown all over.