Crispy Duck Fat Roasted Fingerlings with Cipollini Onions

This duck fat roasted fingerling side dish brings steakhouse energy to your home kitchen. Baby cipollini onions turn sweet and jammy as they roast, while the potatoes develop a crackling, deep-brown crust.

A quick balsamic glaze adds tangy caramelization, and crispy rosemary needles provide a fragrant, crunchy finish. It's a simple but showstopping side that pairs beautifully with roasted meats, steaks, or even a hearty vegetarian main.

The secret to these potatoes is duck fat, which has a high smoke point and a rich, savory flavor that makes everything taste more indulgent. Roasting the potatoes cut-side down on a preheated cast-iron skillet maximizes surface contact, creating an intensely crispy crust while the interiors stay fluffy.

The cipollini onions caramelize slowly, becoming sweet and tender. A final toss with aged balsamic vinegar adds a glossy, tangy glaze that balances the richness.

Ingredients

Why this recipe works

The method here is built on two key techniques: preheating the skillet and roasting cut-side down. Preheating ensures the potatoes start sizzling the moment they hit the pan, which jump-starts browning and prevents sticking.

Cut-side down placement means the largest surface area of each potato is in direct contact with the hot cast iron, producing a deep, mahogany crust that is the hallmark of this dish.

Duck fat is the ideal cooking medium for this recipe. Its high smoke point allows for aggressive browning without burning, and its rich, savory flavor coats each potato with a layer of umami.

The balsamic vinegar is added only at the end, where its sugars caramelize quickly, creating a sticky glaze that clings to the crust without making the potatoes soggy.

Notes and substitutions

Fingerling potatoes are ideal because they are small and uniform, but baby Yukon Golds or red potatoes work just as well. Cipollini onions are sweet and mild, but pearl onions or shallots are fine substitutes. Duck fat can be found in the meat section of most supermarkets or online; if you prefer, beef tallow or ghee will also deliver a rich flavor.

A cast-iron skillet is essential for achieving the best crust because it retains heat and distributes it evenly. If you don't have one, a heavy stainless-steel pan will work, but you may need to adjust the roasting time. The balsamic glaze is quick, so have it measured and ready before you start roasting.

• Duck fat: Beef tallow or ghee for a similar rich flavor; vegetable oil for a neutral option.
• Fingerling potatoes: Baby Yukon Gold or red potatoes, halved or quartered to similar size.
• Cipollini onions: Pearl onions or shallots, peeled and halved if large.
• Aged balsamic vinegar: Regular balsamic vinegar, simmered briefly to thicken slightly.

Equipment

• Cast-iron skillet
• Chef's knife
• Cutting board
• Measuring spoons
• Mixing bowl
• Tongs
• Oven mitts