In medium sauce pan heat 1/2 c. oil (canola), add 1/2 c flour and make roux, let brown slightly. Add 1/2 c. of puree veggies to make a paste. Stir well, then add 2 c. of milk, whisk until well incorporated. When sauce begins to thicken, add 1 c of milk and mix well, then 2 c. of shredded cheese, 1 tsp. coarse sea salt, 1 tsp. of black pepper and 1 TBLS of chopped cilantro. Mix well, heat on simmer till cheese is melted and sauce has thickened. If sauce is too thin, add more cheese, if too thick add more milk.