Preheat your oven to 200°C and line a baking sheet with parchment paper.
Cut the potato into thin wedges and toss them with 0.5 tsp of olive oil, 0.5 tsp of dried oregano, and a pinch of sea salt.
Spread the wedges on the tray and roast for 25 minutes until the edges are golden and crispy.
Grate 0.5 cup of cucumber, squeeze out all excess moisture using a clean kitchen towel, and stir it into the Greek yogurt along with minced garlic and lemon juice.
Dice the remaining 0.25 cup of cucumber, halve the cherry tomatoes, and thinly slice the red onion.
Combine the diced vegetables in a small bowl with the Kalamata olives and the remaining 0.5 tsp of dried oregano.
Heat the remaining 0.5 tsp of olive oil in a non-stick pan over medium-high heat and sauté the seitan strips until they are browned and slightly crunchy.
Assemble your bowl by placing the roasted potato wedges and seitan gyros on one side, adding the Greek salad to the other, and topping with a large dollop of fresh tzatziki.