From Home Cooking by Lori Colwin.
1. Cook two packages of frozen spinach. Drain, reserving one cup of liquid, and chop fine.
2. Melt four tablespoons of butter in a saucepan and add two tablespoons of flour. Blend and cook a little. Do not brown.
3. Add two tablespoons of chopped onion and 1 clove of minced garlic.
4. Add one cup of spinach liquid slowly, then add 1/2 cup of evaporated milk (I use regular milk here), some fresh black pepper, 3/4 teaspoon of celery salt and six ounces of Monterey Jack cheese cut into cubes. Add one or more chopped jalapeños, either fresh or from the jar. (I use 6 ounces of Jalapeño Jack Cheese instead of the regular cheese and chopped pepper. It is what was called for in the original recipe and Colwin adapted it because she couldn't get jalapeño cheese.) Then add the spinach and cook until all is blended.
5. Turn into a buttered casserole topped with buttered bread crumbs and bake for about 45 minutes at 300°.