Ingredients:
* 1 lb. and 1/2 of zucchini
* 1/2 white onion, chopped
* 3 tablespoons butter
* 3 tablespoons flour
* 1 poblano chile
* 2 cups milk
* 1 cup grated cheddar cheese
* Pepper to taste
* Salt to taste
Preparation:
1) Roast the poblano chile over a stove burner or on the gril; once charred all over put it in a plastic bag and leave it there for 10 minutes (this will make the skin come off easily) and peel it.
2) Cook the zucchini, I suggest to cook them in a pot with enough water, a little salt and a teaspoon of sugar, once cooked through then let cool down and slice them in strips.
3) In a skillet melt one teaspoon of butter then fry the chopped onion until translucent; add the two tablespoons butter and add the two tablespoons of flour, stir and once the butter has combined itself to the flour add the milk, season with little salt and pepper and turn off the burner and mix; the sauce will gradually become thicker as it cools down.
4) Place the sliced zucchini in a baking pan and once the white sauce is ready we pour it over to cover them, sprinkle the grated cheese and place the poblano chile strips over everything.
5) Bake in the oven for a few minutes, until the cheese melts and starts to boil. You can finish the “au gratin” crust by broiling the pan in the oven for a few minutes.