Fancy Mashed Potatoes with Crispy Topping

My daughter came home from college, and introduced me to the hugely addictive You Tube series from Bon Appetit. The other night we watched two chefs create perfect mashed potatoes with a delicious crispy topping.

This dish did not disappoint (although, there were A LOT of dishes)

I've adapted the recipe below:

INGREDIENTS
Potatoes
4 lb. traditional mashing potates (Butter, Yukon Gold, etc.)
1 head of garlic +4 cloves
5 sprigs thyme, or dried thyme
2 tsp. black peppercorns, lightly crushed
1¼ cups (2½ sticks) unsalted butter
4 cups (or more) whole milk
1 Tbsp. (or more) kosher salt
1 lemon

2 ½"-thick slices country-style bread, torn into 1" pieces
2 cups potato chips (original recipe recommends kettle style, but we used what we had on hand)
4 Tbsp. unsalted butter
Kosher salt, freshly ground pepper
3 sprigs thyme, leaves picked
1 tsp.  paprika
⅓ cup chopped parsley

RECIPE PREPARATION
Potatoes
Preheat oven to 400°. Using a sheet pan, roast the potatoes (skin on) until a knife cuts through easily -- 60+ minutes.

Cut head of garlic in half crosswise and place in a medium saucepan with thyme, peppercorns, butter, 4 cups milk, and 1 Tbsp. salt.

Using a vegetable peeler, remove wide strips of zest from half of lemon and add to pot; set lemon aside for the topping. Bring mixture to a simmer over medium-high heat, stirring occasionally. Immediately remove from heat, cover, and let sit at least 30 minutes.

When potatoes are done, use a paring knife to remove skins (do this while the potatoes are hot, it's tricky -- use an oven mit and work fast), then mash them immediately. Do not let the potatoes sit whole, even if you are waiting for the milk/butter mixture -- mash them and let them wait. 

Return garlic mixture to a simmer, then pour through a fine-mesh sieve into a pot with potatoes; discard solids. Heat over medium heat and whisk until liquid is incorporated and potatoes are very smooth and bubbling. Taste and season with more salt if needed. Cover and keep warm until ready to serve.

Do Ahead: Potatoes can be made 2 days ahead. Transfer to an airtight container and let cool. Cover and chill. Reheat over medium, whisking constantly and loosening with more milk if needed.

Assembly
Pulse 4 garlic cloves in a food processor until finely chopped, about 15 seconds. Add bread and potato chips and process in long pulses until coarse crumbs form, about 1 minute.

Heat butter in a large ovenproof skillet over medium until foaming. Add breadcrumb mixture and season with salt and pepper. Cook, stirring, until mixture is coated in butter and fragrant, about 1 minute. Transfer skillet to oven; bake , tossingat 350 degrees every 5 minutes, until crumbs and chips are evenly dark golden brown, 15–20 minutes.

Meanwhile, finely grate remaining lemon zest from reserved lemon into a small bowl. Add thyme leaves and paprika and toss to combine.

Remove crumb mixture from oven and immediately toss in thyme mixture. Taste and season with more salt if needed. Let topping cool in pan, then add parsley.

To serve, transfer mashed potatoes to a large bowl and sprinkle topping over.

Do Ahead: Topping (without parsley) can be made 2 days ahead. Store airtight at room temperature.