Mince Filling

1. Heat the olive oil in a large pan over medium-high heat.

2. Brown the mince.

3. Add the frozen veg, rosemary, thyme, salt, and pepper to the pan. Cook until the vegetables soften, stirring occasionally.

4. Add beef stock and tomato paste to the pan, stirring until the paste dissolves.

5. Reduce the heat slightly and let it continue to simmer until the sauce thickens, for about 15 minutes, before turning off the heat.

Cauliflower Mash

1. Place cauliflower florets in a large microwave-safe bowl.

2. Microwave until the cauliflower is very tender, for about 10 minutes.

3. Transfer the cauliflower florets to a blender. Add grated cheese, cream cheese, butter, salt, and pepper. Puree until it has a smooth consistency resembling mashed potatoes.

Construction

1. Use a slotted spoon to transfer the mince filling to a greased baking dish, evenly spreading it along the bottom. 

2. Evenly spread the mashed cauliflower over the mince.

3. Use a fork to roughen the cauliflower surface.

4. Optionally, top with shredded cheddar cheese and paprika.

5. Bake until the peaks of the mashed cauliflower are browning, for about 30 minutes.