Thailand has a number of dishes that would suit your father-in-law. There are a number of simple grilled pork dishes such as *khor mu yang* (grilled pork neck, though you might leave the translation as grilled pork), *mu ping* (pork on a skewer), *satay mu* (pork satay). There are stir fried dishes such as pork with garlic and/or black pepper and roasted pork dishes such as *mu kop* with a crispy salted outside and moist meat inside. Thais love chicken, so fried, grilled and rotisserie chicken are available country wide. And there are plenty of non-spicy dishes available, such as noodle soups, fried noodles (like *pad thai*, *pad seyu*), fried rice dishes, stir fried vegies like asparagus and shrimp, mixed vegies, mild soups like *tom kha gai* (chicken soup), etc. They will find similar dishes in Cambodia and Vietnam as well, though with different names. As they are on a guided tour, their guide should be able to steer them towards specific foods that are not spicy in Cambodia ad Vietnam. They could also get their guide to write a note "I can not eat spicy foods, please do not use any peppers" in the appropriate language for each country.