10 to 12 appetizer servings
If this tart is served warm, diners will need a knife and fork to eat it; if it is at room temperature, the pieces should be firm enough to be picked up and eaten out of hand.
¼ pound thick-cut smoky bacon, cut into half-inch pieces
1 ½ pounds onions (about 2 large; use one yellow and one red for best flavor)
1 teaspoon sugar
½ teaspoon fennel seeds
½ teaspoon brown or yellow mustard seeds
8-ounce package frozen phyllo dough, thawed according to package directions
6 tablespoons unsalted butter, melted
Begin heating oven to 350°F. In large, heavy-bottomed skillet, cook bacon over medium heat, stirring frequently, until it has rendered a good bit of its fat and is starting to crisp up. Meanwhile, peel onions and cut in half from top to bottom; slice from top to bottom so the slices are about 3/16 inch thick at the outside. When bacon is moderately crisp, drain all but one tablespoon fat from the skillet. Add onions, sugar, fennel seeds and mustard seeds to skillet. Stir as best you can; the onions will be overflowing, but will begin cooking down shortly. Cook for 20 minutes, stirring frequently, until onions are reduced in volume and moderately—but not fully—caramelized; reduce heat if onions begin to brown too much or to burn.
While onions are cooking, prepare the tart base (remember to stir the onions occasionally while you’re working with the phyllo). Line a baking sheet with kitchen parchment.
Unroll the phyllo onto your work surface; cover the phyllo stack with waxed paper, then place a lightly damp towel over all. Remove 2 sheets of phyllo, transferring to the parchment-lined baking sheet; re-cover remaining phyllo. Use a pastry brush to lightly coat phyllo with melted butter, starting at the center and brushing outwards. Repeat with remaining phyllo. Lift the long edges of the parchment to fold about ¾ inch of phyllo over, patting down as necessary; let the parchment drop back to the baking sheet after the long edges are formed (the narrow edges do not get folded over). Bake the phyllo until light golden brown and puffed, 16 to 18 minutes; transfer baking sheet to wire rack until needed.
When onions have cooked for 20 minutes, remove from heat; let cool for at least 10 minutes, and as long as 30 minutes. Spread the onions over the baked phyllo, leaving the doubled-over edges clear. Bake at 350°F for 15 minutes, then transfer baking sheet to wire rack to cool for at least 10 minutes; the tart can cool to room temperature before serving if you like. To serve, cut in half lengthwise, then crosswise into 1 ½-inch-wide strips. Serve warm, or at room temperature.
CHOOSING THE BACON
I prefer this dish when it’s made with a good, smoky bacon. I usually use Neuske’s (Wittenberg, WI). Fischer Family Farms (Waseca, MN) also makes wonderful bacon; look for it at Clancey’s Meats, Local D’Lish, Golden Fig and most co-ops. The bacon made by Thielen Meats (Pierz, MN) is also very good, but it is much less smoky; however, it is a wonderful choice if you aren’t looking for that big, smoky flavor.