Whisk the evaporated milk with the cornstarch and salt until combined.
Melt the butter in a pan and whisk in the milk mixture. Bring to a simmer and it with thicken. Remove from heat
Cook pasta to package instructions, but about a minute or two less than it says.
Stir the pasta into the milk mixture right when you strain it. Then add in the cheeses. Stir to combine. The cheese will melt slightly but not all the way.
Preheat oven to 450
Line the mini ramekins with parchment paper, then line them with the slices of cheese. Use photos above for reference.
Pack the mac and cheese into the ramekins, then top with the last slices of cheese.
Place the ramekins onto a baking sheet because they will be dripping oil while baking. Bake at 450 for about 35-40 minutes until the top is very browned and the edges are starting to come away from the paper.
Remove from the oven and allow to cool for 5 minutes. Use a knife to make sure the cheese isnt sticking to any edges. Remove from the ramekins, then remove the paper. Plate and serve.