This rich and flavorful dip easily becomes a fun and fancy take on a cheese and spinach dip when topped with crispy pancetta and crunchy fried shallots, which are essentially like mini onion rings. The complex flavors here elevate this dip to more than just your average party fare. It has texture, three cheeses for maximum flavor, and makes enough to serve a crowd. Although be warned, if you make this for a party once, be prepared to be asked to make it again and again!
How to Make It
Soak shallot slices in buttermilk at room temperature while preparing remaining ingredients.
Cook pancetta in a large straight-sided skillet over medium until crisp, about 15 minutes. Drain pancetta on paper towels. Add oil to skillet, and increase heat to medium-high. Add onions, and cook, stirring every 5 minutes, until caramelized and brown in color, about 45 minutes. (Add up to 1 cup water, 1/4 cup at a time, after 40 minutes, stirring to loosen browned bits from bottom of skillet, if onions begin to stick.)
Reduce heat to medium; add spinach, kale, garlic, and three-fourths of the cooked pancetta to skillet. Cook, stirring occasionally, until greens are wilted, about 5 minutes. Add butter, and cook, stirring occasionally, until butter is melted. Stir in 1/2 cup of the flour. Add milk, 1 cup at a time, stirring until smooth after each addition. Bring to simmer. Add Asiago, Gruyère, and fontina, and cook, stirring often, until melted, about 10 minutes. Stir in vinegar and 1 tablespoon of the salt. Keep warm over low heat.
Pour oil to a depth of 3 inches in a deep, straight-sided pot; heat over medium-high to 350°F. Combine cornstarch and remaining 1 1/2 cups flour and 1 teaspoon salt in a large bowl. Dredge soaked shallot slices in flour mixture, and carefully place in hot oil. Cook until lightly golden and crisp, about 2 minutes. Remove from oil, and drain on paper towels.
Transfer dip to a serving bowl, and top with crisp fried shallots and remaining pancetta. Serve with naan bread or pita chips.