Dude it’s rough. I am Mexican and still have my mom send me stuff from home a few times a year haha. Mi Salvador Mexicano (small store and restaurant next door) in Chelsea is pretty good but limited selection tbh. They do have meats for menudo as well as an ok pastry section and all the candies and snacks. If It’s more convenient to go West, Patel Bros grocery store, on Moody street in Waltham, has a very good selection of dried chiles and salsas though. They may have what you need. There’s a few Guatemalan stores in the area too that I feel like I’ve seen tripe at. At the very least you can stock up on dried goods and grab some good corn atole!