For the broth, add the ginger, garlic, spring onions and shiitake stems, along with 750ml of water to a medium pot. Bring to a boil, then reduce to a gentle simmer and cook, covered, for 30 minutes. Remove the vegetables with a slotted spoon and discard. Whisk in the miso and keep warm on the stove.
For the mince, add the sunflower oil to a large, non-stick frying pan on medium high heat. Add the spring onion whites and cumin and cook for 2-3 minutes until fragrant. Add the tempeh and chopped shiitake, along with ⅛ teaspoon salt and cook for 10-15 minutes, until starting to char and caramelise, stirring often.
In a bowl whisk together the ginger, garlic, chili oil, soy sauce, smoked paprika and lime juice. Add to the pan and saute for another 2-3 minutes until the tempeh is evenly coated with the sauce.
Toss all of the ingredients for the avocado salsa together, along with the reserved spring onion slices.
To serve, divide the rice into large bowls, ladle in the broth and top with the tempeh, avocado salsa, lime zest and a drizzle of sesame oil.