1. Preheat the oven to 400°F, soak the potatoes in cold salted water, and heat a large skillet over medium-high heat.
2. Once the skillet is hot, add olive oil and onions, and let them sauté for 3 to 5 minutes.
3. Once sautéed, add the peas, asparagus, and garlic to the skillet and let them sauté for another 3 to 5 minutes.
4. After that, add the lamb to the skillet sprinkling the parsley, rosemary, thyme, salt, and pepper on it, then mix with a cooking spoon or spatula and let it cook for 5 to 8 minutes.
5. While the lamb cooks, drain the potatoes, transfer them to a large pot with fresh water, and bring it to a boil for 10 to 15 minutes.
6. Once the lamb is cooked, add the tomato paste, vegetable broth, and arrowroot starch, stirring everything together, and then let it simmer for 5 to 8 minutes.
7. Once the potatoes are boiled, drain them again and place them back in the pot with the coconut milk, parmesan cheese, garlic, garlic powder, salt, and pepper to mash together with a masher or blend together with a hand blender.
8. Once the lamb and potatoes are ready, pour the lamb mixture into a baking dish and top it with the mashed potatoes, smoothing them out into an even layer.
9. Then place the baking dish in the oven and let it cook for 20 to 25 minutes.
10. After that time, remove it from the oven and let it cool for 10 to 15 minutes.
11. Once cool, serve the shepherd's pie, garnish with the chopped parsley, serve, and enjoy!
