Slice the top and bottom from the zucchini and discard. Cut the zucchini in half lengthwise. Heat a griddle pan over a high heat. Add the zucchini halves cut side down and griddle for 3-4 minutes each side or until cooked through and char lines appear. Keep warm until ready to serve.
Heat the oil in a skillet over a medium heat. Crush the garlic and finely chop the rosemary and mushroom. Add the onion, garlic, mushroom, rosemary, thyme leaves and lemon zest to the skillet. Sweat gently for 2-3 minutes until tender.
Add the ground almonds, salt and pepper and stir to combine, cooking for a further minute or two until golden.
Divide the stuffing mixture between the two zucchini boats.
Roughly chop the cranberries and scatter over the zucchini boats and sprinkle with nutritional yeast to serve.