Heat a large skillet over med-low heat, with 1 tbsp of olive oil. Fold in chopped red onion and spinach leaves.
Cook for about 3 min stirring occasionally. Add parma ham half-way through, and continue to cook until the spinach soften.
Season with salt, pepper and a pinch of nutmeg and allow to cool.
In a large bowl whisk together eggs, ricotta and parmesan cheese. Season with salt and pepper.
Fold the spinach and ham into the egg mixture and mix until combined. Finally mix in spring onion, thyme and season to taste.
Spray with oil a non-stick muffin tin. Divide the frittata mixture evenly, filling 2/3 of each mold.
Bake for 15 min or until crispy and golden on top.
Remove from the oven, allow to cool and serve immediately or at room temperature,
Store in an air-tight container in the fridge for up to 2 days.