Preheat the oven to 375º F. If you’re using pâte brisée, roll it out into a 9-inch pie or tart pan, then prick the base with a fork. Cover the crust with a large piece of aluminum foil and fill it with pie weights. Blind bake for 20 minutes. Remove from the oven and let it cool.
In a cold saucepan, combine the olive oil and minced garlic. Set over medium-low heat, gently warming the garlic without browning it, about two to three minutes. You’re just mellowing out the raw garlic bite—it will finish softening in the oven. Remove from heat.
Stir in the melted onions, chopped thyme, and sea salt to the saucepan with the garlic, mixing everything well.
Place the prepared tart shell, puff pastry, or pizza dough on a sheet pan. Evenly distribute the onion mixture in the shell. If using puff pastry or dough, leave about an inch of dough uncovered around the perimeter.
Top with the anchovies and olives. I like to arrange the anchovies in a lattice pattern, tucking one olive into each diamond-shaped opening.
Bake for 20 minutes. Puff pastry should be golden and crisp within this time, but if you’re using other dough, check the package instructions. The onion, anchovies, and olives are pretty forgiving if they need a bit more time. Serve warm or at room temperature.
Pissaladière is a classic dish with roots in both Genoa, Italy, and Nice, France—two cities that share a close border and a love of similar regional ingredients. Traditionally, it’s made with a dough similar to pizza, but in Provence, you’ll sometimes find puff pastry used as the base, à la Julia Child. I’ve tried both and occasionally serve it in a tart shell with pâte brisée.