Ground pork is becoming more common in the meat case. You can also ask your butcher to grind it. Usually the lean-to-fat ratio is similar to ground chuck. We find French hamburger buns at Publix grocery stores.
This was better than I expected! Anytime I open up a can of chipotle chilies for a recipe I look for other recipes that I can incorporate the rest of the chilies into. This combination of ingredients intrigued me so I thought why not? The only changes I made were subbing shallots for the green onions as that is what I had on hand and used a small amount of spring mix instead of butter lettuce. Will make this one again for sure and may even offer it at a cookout to change it up and surprise the skeptics.