Preparation
Preheat broiler on high or oven at 400°F.
Heat a medium, deep skillet over medium heat. Add oil and butter. When the butter melts into the oil, add the flour and combine. Gently cook, whisking flour and butter together, until smooth and flour has had a chance to cook, about 1 minute. Slowly add milk while continuing to whisk.
Gently bring milk to a bubble while stirring frequently. Allow the milk to thicken a bit then stir in 2 cups of cheese, a handful at a time.
Add 1-2 cups of leftover chili, stir to combine thoroughly.
Taste and add a little salt, if you like. Add cooked pasta to sauce and coat completely by turning over and over in the cheese sauce.
