1 pound medium-size potatoes, scrubbed
4 ounces sorrel, stemmed and washed
1 garlic clove
¾ cup milk
¼ cup Gruyere, grated
¼ cup Parmesan, grated
salt & pepper to taste
Olive oil/butter for baking dish
Place potatoes in a wide saucepan and cover with water. Add salt to taste and gently boil potatoes for 20 minutes, or until tender all the way through but firm enough to slice.
When cooked, slice about ½ inch thick, or if you prefer, cut in dice. Transfer to a large bowl.
Stem and wash sorrel leaves. Heat a wide skillet over high heat and add the sorrel, in batches if necessary. When all of the sorrel has wilted, remove from heat, rinse briefly with cold water, remove any excess water, and then chop medium-fine.
Toss together potatoes, sorrel, and season with salt, pepper, and garlic.
Preheat oven to 375 degrees.
Rub sides and bottom of a 2-quart baking dish with olive oil and garlic.
Beat eggs in a medium bowl. Add salt to taste. Whisk in milk. Add to potatoes and sorrel and stir well to distribute sorrel evenly throughout the mixture. Stir in cheeses and freshly ground pepper, and scrape into the baking dish.
Bake 45 minutes, or until set and the top and sides are nicely browned. Remove from the heat and allow to sit for 10 minutes or longer before serving.
Recipe adapted from: https://cooking.nytimes.com/recipes/1015967-potato-and-sorrel-gratin#notes_section