POTATOES Bring the water to a boil, adding potatoes as they're prepped. Cover and cook at a medium boil until fully cooked (a knife will slip in and out easily). Drain into a colander. Let cool (I skipped this step which I think made it harder to cut thin and even slices). Peel, then slice thin. POBLANO PEPPER SAUCE In a large skillet, heat the olive oil til shimmery. Add the peppers and onion and saute until soft, about 15 minutes. Transfer to a food processor and process til smooth, as much as you can. Add a splash of the cream, and continue processing until smooth. Then add rest of cream, the milk and garlic but only give it a quick whirl, you're not trying to whip. SEASON. ASSEMBLY Preheat oven to 350F. Grease a baking dish. Spread bottom with about 1/4 cup of the poblano sauce. Arrange a layer of potatoes. SEASON. Top with just enough sauce to cover. Cover with half the cheese. Arrange a second layer of potatoes. SEASON. Top with more sauce to cover (if there's some leftover, I would probably save for something else, the full amount may be too much). Top with remaining cheese. Bake for about 45 minutes or until bubbly and beginning to brown on top. If needed, place under broiler to finish browning. Cover and let rest for 15 minutes to thicken before serving.