Broccoli or Cauliflower Cheese Soup

1 pound broccoli or cauliflower, coarsely chopped
6 tablespoons ( 3/4 stick) butter
1/4 cup all purpose flour
4 cups vegetable stock
2 cups heavy (whipping) cream
Freshly ground black pepper
1 cup chopped yellow onion
1 tablespoon minced garlic
2 tablespoon minced jalapenos
1 cup freshly shredded cheddar cheese
1 cup freshly shredded Emmentaler or Jarlsberg cheese

Place broccoli or cauliflower in steamer rack and steam until just tender, about six minutes, remove from heat, rinse with cold water to stop cooking and preserve color, drain and chop finely, set aside
In stock pot, melt three tablespoons of butter over low heat, add flour and cook, stirring constantly, for about three minutes
Whisk in stock and cream, increase heat to medium high and bring to boil stirring constantly
Reduce heat to low and simmer, stirring occasionally, until thickened, about ten minutes
Season to taste with salt and pepper
In a skillet, heat remaining butter over low heat
add onion and saute until soft but not golden, about eight minutes, add garlic and chile and saute a minute longer
transfer to the cream mixture
Add the broccoli or cauliflower and the cheese and cook over low heat, stirring almost constantly, until cheese melts, about five minutes, do not boil
Season to taste with salt and pepper