First things first, let's get that dough ready. In a large bowl, mix the flour, cornmeal, salt, and sugar. In another bowl, combine warm water and yeast. Let it sit for 5-10 minutes. It should start to bubble. Gradually add this to the dry mix, followed by the melted butter. Knead until smooth. Cover it and let it rise for about 1 hour until it doubles in size.

While your dough rises, you can whip up the filling. In a large skillet, heat olive oil over medium heat. Add the diced onion, carrot, and celery. Cook until they soften, stirring occasionally. Then, add minced garlic and lamb. Cook until the lamb is browned. Sprinkle the flour over the meat mixture and stir to combine. Gradually add beef broth while stirring, and let it thicken. Add thyme, rosemary, and corn. Mix well, then remove from heat.

In a pot, boil the chopped potatoes until tender. Drain well. Mash with butter and milk, then season with salt and pepper. Set aside.

Now, preheat your oven to 425°F (220°C). Roll out your dough on a floured surface to fit your greased pizza pan. Spread the lamb mixture evenly over the dough, followed by the mashed potatoes. Sprinkle cheddar cheese, smoked paprika, and cumin on top.

Pop that creation into the oven for around 25-30 minutes or until the crust is golden brown and the cheese is bubbly. Your kitchen will smell heavenly.

Once the pizza is ready, let it cool for a few minutes before slicing. Serve hot, and get ready for compliments. You did it!