Mmmmm...

Anyone want to guess what these are the ingredients to?
(Hint: From one of my favorite places to eat):
4 guijillo chiles
2 teaspoons cumin seeds
1 teaspoon ground cloves
10 allspice berries
1/3 cup Mexican oregano
12 sprigs fresh thyme
6 garlic cloves
1 Spanish onion, roughly chopped
1/3 cup cider vinegar
1 (6 to 8-pound) beef roast
Salt and pepper
1 (2-pound) package dried avocado leaves