Preheat the oven to 180C. Grease a slice pan or line with baking paper.
Spray a non-stick fry pan with cooking spray or use a small amount of oil. Add chopped onion to the pan and cook for a few minutes until translucent.
Add grated sweet potato to pan. Stir occasionally to avoid potato bits from burning. Cook until soft. Add in garlic and cook for a few more minutes. Remove from heat.
Whisk all eggs together in a large bowl. Slowly introduce flour to eggs. Then add ricotta until combined. Once fully mixed, introduce potato mixture, lentils, chopped spinach, chives and parsley. Pat excess moisture from grated zucchini with a paper towel and then add to bowl.
Distribute mixture evenly in the slice pan. Bake for around 30 minutes or until cooked through. Serve with a simple salad.