Add oil, chicken broth and taco seasoning for chicken to a gallon zipper bag. Smoosh it around until well combined. Then add chicken legs. Smoosh around again, to coat chicken pieces. Seal and place in refrigerator to marinate for at least 4 hours (up to overnight).
Preheat oven to 375degF.
On a baking rack, over a parchment paper covered baking sheet, line out chicken legs. Bake for 30 minutes. (or until thickest part reaches 165degF, internally).
Remove chicken from oven. Then remove meat from the bones. Chop into small pieces.
Spray a baking rack (over a parchment paper covered baking sheet) with oil.
Add portion of cheese and chicken to center of flour tortilla. Tightly roll up (leaving ends open) and line up on baking rack. Repeat with remaining tortillas. Once done, spray (generously) with cooking spray. Place in oven for 15 minutes.
To make the queso, add one cup of chicken broth to a large measuring cup, along with cornstarch and taco seasoning. Whisk until thoroughly combines. Add to a small sauce pan over medium high heat. Bring just to a bubble then add remaining chicken broth and jalapenos.
Reduce heat to medium and let thicken for 5 minutes (whisking occasionally). Then add cheese, one handful at a time, until fully melted in.
Serve up 3-4 tacos with a dish of queso for dipping.