Combine warm water and yeast. Let sit until mixture starts to foam, about 5 minutes.
Mix tomatoes, cheese, cumin, prosciutto, and rosemary together in a mixing bowl. Set aside.
Mix flour, salt, pepper, and nutmeg together in a separate large mixing bowl. Make a well in the center and add tomato mixture, eggs, butter, yeast. Mix until mixture pulls from the sides. Dough will be sticky with a soft texture.
Lightly flour a work surface. Knead dough until smooth and elastic, adding more floor as needed to keep it from sticking to the work surface, about 10 minutes.
Oil bottom and sides of a clean bowl. Place dough in bowl and cover with clean cloth or towel 2 hours. Punch down and let rest 10 minutes.
Lightly oil a baking sheet. Shape dough into round loaf and place on sheet. Cover until doubled in size, about 1 hour.
Preheat oven to 350 degrees F (175 degrees C).
Bake bread in preheated oven until crust is golden brown, about 1 hour 15 minutes. Cool on a rack to room temperature.