Toss together jack cheese, cheddar and cornstarch.
Heat oil in large pan over medium low heat. Add garlic, cumin coriander and oregano. Cook til garlic softens, about 1 minute.
Add lager and bring to a simmer over medium heat. Whisk in cheese mixture a handful at a time, letting each addition fully melt before adding the next. Whisk in chipotles and zest and transfer to a warm fondue pot. Makes 2 1/2 cups