The best bread, in my opinion, is the artisan, a bit harder, but not too dark. Try to pick one that is a bit lighter, because it will get a tad darker in the oven. You can use, Mexican Cheese blend, or Italian Cheese blend, too. Mozzarella, a bit thicker slices are recommended. You can add about 1/2 stick of garlic-herb butter before adding the cheese, then on the end and before baking drizzle more butter. It gives you this amazing taste and aroma. Recommending because I tried it! The picture below: I used 1/4 c of Irish Butter, added herbs, garlic powder, mix but keep it cold. Add in between the cracks, then add cheese. Before baking, melt 1/4 c of butter with garlic and herbs and drizzle on top. So good!