Dissolve the cornstarch in the water.
Add the pecan to 1 cup of milk and blend in a blender.
Heat the rest of the milk along with the cinnamon stick and vanilla in a large pot.
When the milk begins to boil, add the pecan-milk mixture and let boil for 3 minutes.
Add the evaporated milk and La Lechera Sweetened Condensed Milk to the pot, stir, and let boil for 5 additional minutes.
Add the cornstarch that was dissolved in water and stir until it reaches your desired consistency.
Serve with freshly baked sweet bread or by itself.