In a pot, combine chicken, taco seasoning, canned tomatoes, and green chilies. Add water or chicken stock until the chicken is covered. Simmer for 25-30 minutes or until the chicken is fully cooked and shreds easily.
While the chicken is cooking, prepare the sauce. Cut the stems of the jalapenos and halve them. Remove seeds for a milder taste. Peel and halve the onion.
In a pan, sauté jalapenos and onion in 2 tbsp of oil for 5-7 minutes. Add lime halves and garlic cloves, cooking for an additional 3-4 minutes until charred.
Transfer sautéed ingredients, lime juice, ½ cup oil, and chicken bouillon to a blender or food processor. Blend until smooth, adding more oil if needed. Set aside.
Shred the cooked chicken and keep it in the juices.
Heat 2-3 cups of oil in a pan over medium heat.
Wrap corn tortillas in a damp paper towel and microwave for 2 minutes. Carefully handle the hot and steamy tortillas.
Place ¼ cup of shredded chicken in the middle of each tortilla, roll tightly, and fry seam side down in the hot oil using tongs.
Cook for 2-3 minutes per side or until golden brown, then transfer to a cooling rack. Repeat for the remaining flautas.
Plate the flautas and top them with the green sauce and your preferred toppings. Enjoy!