Preheat the oven to 180°C.
Cube the tofu and zest the lemon. Slice the zucchini, mushrooms and peeled potatoes into thin slices. Cut the pepper into pieces. Cut the onion in half and separate the individual layers from one another.
Blend the sunflower oil with the spices and lemon zest. Put the garlic through a garlic press and add to the oil.
Thread all of the vegetables and the tofu onto the skewer, alternating as you go, and brush the marinade on them to make them crisp up when grilled.
Place the skewers on a baking sheet lined with parchment paper and bake at 180°C in a convection oven for approximately 15 minutes. You can also place them under the broiler for an additional 7-8 minutes. In warm weather, you can grill them on the barbecue. Serve with salads and dips.