Preheat the oven to 425 degrees F. Line a baking tray with parchment paper and set aside.
Fill a large pot with water and bring to a boil. Once boiling, add the carrot noodles for just 2 minutes to lightly soften. If you’d like them softer, leave them for 3-5 minutes. Drain into a colander and set aside. Note: you can also serve the carrot noodles raw and skip the boiling step (it’s personal preference.)
While waiting for the water to boil, prepare the meatballs. In a large mixing bowl, combine the ground lamb, parsley, oregano, garlic, cumin, salt and pepper. Mix well. Using your hands and about 2-3 tablespoons of meatball mixture at a time, form balls and set onto the parchment paper lined baking tray. Continue until 16-18 balls are formed. Brush each with the olive oil. Bake in the oven for about 12 minutes or until no longer pink inside.
Meanwhile, divide the carrot noodles evenly into six bowls. Chop the spinach and divide evenly into the bowls. Place the onions and tomatoes in a bowl and toss together. Sprinkle the spinach with the chopped onions and tomatoes. Set all aside.
Prepare the tzatziki. Put all of the ingredients for the tzatziki into a food processor and pulse until creamy. Taste and adjust if necessary.
Once the meatballs are done, finish assembling the bowls. Add three meatballs per bowl and drizzle with the tzatziki sauce. Garnish with mint and serve.