Because leeks are so very costly per pound in the US, it pains me, PAINS ME, to throw away leek tops the way most French cooks do. I’ll do it if I absolutely have to—say, when the green tops look particularly roughed up and fibrous, or when I know I won’t have time to deal with them—but otherwise, I slice ‘em up and use ‘em any way I can. One of those ways I can is in Irish champ.

Champ is an Irish mashed potato dish that’s traditionally made with scallions. It is homey and satisfying and, if you ask me, even better when made with leftover leek greens.

I’m not exactly an objective judge: leeks are some of my favorite vegetables. (I have been known to choose dishes from restaurant menus on the sole basis that they are made with or come with leeks.) It could also be that leeks also add texture and body to the mashed potatoes for a side dish that feels a little more like a vegetable dish than a starch.

Leek champ couldn’t be an easier dish to make, but in reading about it and playing around with it, I’ve added a few kitchen tricks. First: Add a little water to the sautéing leeks to make sure they don’t brown or burn. Personally, I like my leek champ rough and rustic, with big bits of leeks laced through, but you can always make the dish more elegant by finely slicing the leek greens instead. Second trick: Add the milk to the cooked leeks to let it become infused with flavors. (This is my nod to Irish cookbook author Darina Allen’s technique of boiling the milk with the scallions in her traditional recipe.) This step also warms the milk before the potatoes are added. And finally: Potato water. Adding it to the mash lets you cut down on butter and milk without sacrificing texture. And speaking of butter and milk…you can always replace them with olive oil and a vegetable milk for a vegan version.

I’ve served leek green champ with everything from seared scallops to roasted vegetables, but I think my favorite way to eat it is all on its own in a bowl for dinner, generously sprinkled with Cheddar cheese.

1 ½ lb. russet, Idaho, or Yukon gold potatoes, peeled and cut into chunks
3 Tbs. (45 g.) butter
4 cups (250 g.) washed, sliced leek greens (Slice the leek greens first, dunk in a large bowl of cold water to remove the sand and grit, then drain)
¼ cup milk
salt, pepper

Bring the potatoes and enough salted water to cover them by 1 inch to a boil in a large saucepan. Cook the potatoes at a rolling boil 15 to 20 minutes, or until soft.

Meanwhile, heat 2 Tbs. (30 g.) of the butter in a large saucepan over medium heat. Add the leek greens, a pinch of salt, and ¼ cup water, cover, and reduce heat to medium low. Let the leek greens cook 10 minutes, or until softened, stirring occasionally. Add the milk, remove from the heat, and set aside.

Drain the potatoes, and reserve ½ cup cooking water. Mash the potatoes with the leek mixture and the remaining butter in the saucepan, adding enough cooking water to make a smooth, thick purée. Season with salt and pepper. Serves 6