To make meatballs: In a medium bowl, combine ground turkey, zucchini, green onion, basil, ginger, garlic, red curry paste, fish sauce, coconut milk and red pepper flakes. Mix well.
Make 28 meatballs by spooning heaping 1 tablespoon of mixture and rolling between your hands. Lay on a cutting board or plate. Set aside.
To make sauce: In a small bowl, whisk together coconut milk, tomato paste, red curry paste, fish sauce, red pepper flakes and kaffir lime leaves. Set aside.
Preheat large ceramic non-stick skillet on medium-high heat and spray with cooking spray. Add meatballs and cook until brown or for 2-3 minutes, turning a few times. No need to cook the meatballs through.
Add the sauce, reduce heat to medium and simmer for 15 minutes, uncovered.
Serve warm with brown rice or brown rice noodles. Add garnish like fresh cilantro and green onions.
Notes
Make ahead: Make meatballs and sauce up to 24 hours in advance. Store covered separately in the fridge.
Store: Refrigerate in an airtight container for up to 5 days.
Freeze: Fully cook, cool completely and freeze in an airtight container for up to 3 months. Thaw on a stovetop covered on low.
Kaffir lime leaves: You can buy kaffir lime leaves in any Asian store or online. They are sold dried and last forever in a sealed container. If you don't have any, omit.