Created by breezermom on October 1, 2017
Step 1: In a large pot of boiling water, blanch the chard until wilted, about 1 minute. Drain the chard, squeeze it dry, and chop. Be sure to remove any excess moisture.
Step 2: Heat the oil in the pot. Add the leeks and a pinch of salt. Cover and cook over medium to medium low heat, stirring, until tender, 7 minutes. You know your stove -- if it cooks hot make it medium low, if it cooks low, make it medium. Uncover, add the garlic, and cook, stirring, until fragrant. (about 2 minutes). Add the chard, season with salt to taste and remove from the heat.
Step 3: Preheat the oven to 425 degrees. Butter or grease a 2 qt casserole dish.
Step 4: In a large saucepan, melt the butter. Stir in the flour over moderate heat to form a paste. Gradually whisk 1/3 of the milk and cook, whisking, until the mixture starts to thicken. Repeat two more times with the remaining milk.
Step 5: Bring the sauce to a boil, whisking constantly. Reduce the heat to low and cook, whisking often, until thickened and no floury taste remains, about 10-15 minutes. Whisk in the cheeses and the nutmeg. season with salt and pepper.
Step 6: Combine the sauce and leeks/chard mixture. Season with salt and pepper to taste.
Step 7: Transfer to the prepared casserole dish. Bake in the upper third of the oven for 25 minutes. Let rest for 10 minutes before serving to prevent burning your mouth.