In a large saucepan, melt the butter over medium heat. Add the chopped onion, and cook until tender.

Add the tomatoes, habanero peppers and canned chiles (do not drain the chiles). Bring to a boil.

Reduce their heat to low. Simmer uncovered for 12 to 15 minutes.

In a bowl, toss the Cheese Loaf and Shredded Habanero Cheddar cheeses together with the cornstarch.

Gradually add your cheese mixture to the saucepan, stirring until the cheese melts and your dip is heated throughout.