Mexican Fajitas Recipe. If there is one Mexican food that I simply can’t resist, it has to be fajitas. The combination of meat, veggies, cheese, caramelized onions, and spices is simply irresistible. Since they are a meal on their own, though, it is sometimes hard to come up with what can you serve with fajitas. Here are my favorite recipes for sides that will make your fajita experience even better. They fit the Mexican vibe with their delicious flavors and popping colors.