- Preheat oven to 375°F.
- Wilt spinach by placing in microwave safe bowl; cover with cling film. Poke two holes in the plastic wrap and microwave on high for 2-3 minutes. Set aside to cool. Once cool drain by squeezing well.
- In a large bowl whisk together eggs, egg whites, milk, mustard, pepper and rosemary.
- Add ham, Swiss cheese and cubed bread and combine well.
- Place half of the bread mixture in a baking dish, top with spinach then peas. Cover with remaining bread mixture and pat down with a spatula.
- Cover with foil and bake for 40 minutes. Uncover and top with bacon crumbles and mozzarella.
- Return to the oven, uncovered for 20 minutes.
- Let rest for 15 minutes prior to serving.