Preheat your oven to 400°F (200°C).
In a small bowl, combine the dry soya mince with the vegetable broth and let it sit for 10 minutes to rehydrate.
Steam the cauliflower florets until very tender, then transfer to a food processor with the Greek yogurt, sea salt, and black pepper. Pulse until smooth and velvety.
Heat olive oil in a large skillet over medium heat. Add the diced onion and carrots, sautéing for 5-7 minutes until softened.
Stir in the minced garlic, tomato paste, tamari, and dried thyme, cooking for another 2 minutes until fragrant.
Add the rehydrated soya mince (including any remaining liquid) and the frozen peas to the skillet. Simmer for 5 minutes until the sauce thickens slightly.
Transfer the mince mixture to a small baking dish and spread the cauliflower mash evenly over the top.
Bake for 15-20 minutes until the edges are bubbling and the top is lightly golden.
Let rest for 5 minutes before serving.