Boil chicken in pot until cooked. Set aside. Chop tomatoes, onions, garlic and jalapeno. In a large frying pan add 2 tbsp oil and chopped veggies. Cook on medium heat. Slice plantains into 1 inch lengths. Add the rest of the oil to second frying pan. Mash plantain slices into small pancakes. Fry plantains until golden brown and remove. Add seasoning salt to the veggies and and suatee on low heat. Use two forks to shred the chicken. Slice avocados. Combine into tostadas.