Here's one last dinner recipe to close out the week. This is from my book, Not Your Mother's Casseroles, and it really expresses the way I like to make vegetable casseroles. I find that many casseroles and gratins smother the vegetables with dairy, grains, and other peripheral ingredients. But I want to taste the vegetables — especially when, like here, they are fresh and springlike — leeks, fennel, potatoes, onion, garlic. So I let them stand on their own in this ultra-simple gratin. It's all about the vegetables.
The tradeoff, with a very simple vegetable gratin like this one, is that you don't get a pretty, sliceable dish. This is basically a big vegetable bake, jumbled up and jostling with fresh-sliced vegetables. I keep the dairy (sour cream, Grana Padano cheese) at a bare minimum — just enough to hold the vegetables together. So this isn't an indulgent, holiday-style gratin with more cream than potatoes. This is a weeknight vegetable bake; it comes together in just 20 minutes or so (especially if you have a mandoline, which is really, really helpful for this dish — almost mandatory) before it goes into the oven to bake for an hour.
The flavors are simple and straightforward — plenty of savory, onion-y fragrance, and a touch of sweetness from the potatoes. The potatoes get quite soft but the fennel keeps its slight bite; I really like this mix of textures. There's a creaminess to the whole thing, too, from the natural juices of the vegetables, mingling with just a bit of sour cream and cheese. There aren't any complicated spices or flavors happening here. It's all quite simple, an ode to the vegetables we have now, early in the spring.
This simplicity and plainness means that a scoop of these baked vegetables would be perfect with a roasted chicken, or a rich dish of pasta. Serve it drizzled with chicken or meat juices, or just eat it plain, with a glass of white wine and an extra sprinkle of crunchy kosher salt and fresh black pepper.
Creamy Spring Vegetable Gratin with Grana Padano The idea of spring vegetables is a bit deceptive. Although vegetable gardens are sprouting and the trees are turning green, there is actually very little ready to eat yet! So a spring vegetable gratin turns to those lovely over-wintered vegetables that are still so fresh and appealing in the early springtime, like leeks and crisp fennel.
2 small fennel bulbs, trimmed 2 large leeks 2 large russet potatoes (between 3/4 and 1 pound), peeled 1 large onion, thinly sliced 4 cloves garlic, minced 1 cup sour cream 1 teaspoon salt 1/2 teaspoon ground nutmeg 1/4 teaspoon freshly ground black pepper 1 cup grated Grana Padano cheese
1. Preheat the oven to 400°F. Lightly grease the baking dish with olive oil.
2. Using a mandoline or very sharp knife, cut the fennel bulb into thin slices. (Note: I aim for about 1/8-inch thick slices. A mandoline or food processor is almost mandatory for this.) Cut each leek in half lengthwise and rinse to remove any grit; pat dry. Slice the leek halves into 1-inch-wide half moons and separate each layer. Slice the potatoes as thin as the fennel (just use the same setting on the mandoline or food processor), and toss all these vegetables into your largest bowl with the onion and garlic.
3. Stir in the sour cream, salt, nutmeg, pepper, and cheese. (The mixture will be thick and just barely covered with the cheese and sour cream.) Scrape into the prepared baking dish and cover tightly with foil. (This amount of vegetabes will pack the baking dish very full — but after baking it the volume will go down considerably.) Bake for 45 minutes, then remove the foil and bake for an additional 15 minutes to let the top brown. Let stand for 10 minutes, then serve hot in big scoops.
Using a mandoline to slice potatoes, fennel, and an onion.
Recipe Notes: • I like to add some fresh herbs to this as well, if they are on hand. Some snippets of the fennel fronds are nice, or a few snipped sorrel leaves. I also like to garnish the top of the gratin with more of the feathery fennel fronds when serving. • If you can't find Grana Padano (here's a primer on this cheese) use another hard, salty cheese like Parmesan or aged Asiago. • On the sour cream: I have only made this with full-fat sour cream. I would not recommend using lower-fat sour cream, but you're welcome to try. There's only 1 cup in this entire casserole, so I think using a higher-fat product is better here.