Preheat oven to 200°C/400°F/Gas Mark 6 and grease a baking dish with olive oil.
In a medium bowl, whisk together the eggs until light and slightly foamy. Add the garlic, onion, zucchini, kale, peas, cheese, half the thyme leaves, and milk. Mix until combined. Stir through the flour until smooth and season with sea salt and freshly cracked pepper.
Pour the mixture into the prepared baking dish, arrange the 2 remaining thyme sprigs on top.
Place into the preheated oven and bake for 35 minutes, or until the filling is cooked through and the top is golden brown.
Once cooked, remove from the oven and allow to cool completely. Serve with rocket leaves and drizzle with olive oil.