Caramelized Onion Tart with Gorgonzola
Blog post by Phyl.
This week’s Modern Baker Mondays recipe veers sharply away from the sweet puff pastry recipes we’ve been making recently to bring up something savory, tangy, and, OK, a little sweet. The combination of caramelized onions, blue cheese, and tarragon is genius. These flavors play off one another to bring out the best qualities in each of them.
As with all the recipes in this section, this tart is built on a crust made of puff pastry. The full recipe makes a 12 x 15-inch tart. I wanted to halve the recipe, so I used a 6 x 7 1/2-inch pan, right? Wrong!!! I used an 8 x 11 1/2-inch pan, which is very close to half the size of the jellyroll pan called for in the recipe.
How, you say? Let’s do the math. A 12 x 15-inch pan has a surface area of 180 inches (12 x 15 = 180), half of which is, of course, 90. And 8 x 11.5 = 92; pretty darn close to 90. So, I used half the puff pastry called for in the recipe, rolled it out to fit the pan, and stuck the crust in the fridge until I was ready for it.
Next, I prepared the caramelize onions. There are two basic methods for caramelizing onions — the real way, and the fake way. The real way involves cooking the onions over very low heat in butter or oil with a pinch of salt for a long time (upwards of an hour). The “fake” way, which really doesn’t involve caramelizing the onions at all, is to sauté the onions in butter or oil and add sugar and balsamic vinegar to mimic the color and flavor you get when you caramelize onions.
When I read the ingredients to this recipe and saw that it called for both brown sugar and balsamic vinegar, I figured we’d be faking the caramelized onions. But then I read the recipe and saw that the onions are cooked over low heat for 40 minutes, and I realized that Nick had combined the long, slow cooking and natural caramelization with sugar and vinegar for added flavor. I should know by now to trust him, shouldn’t I?
The onions looked and smelled wonderful while they cooked. And the flavor was as good as any caramelize onion I’d ever had.
With the crust and caramelized onions at the ready, all that was left to do was crumble some blue cheese and chop fresh tarragon. I used a mixture of chevre blue and buttermilk blue for the cheese. The goat blue was firm and very flavorful; and the buttermilk cheese was soft and tangy.
To assemble the tart, I poked the crust with the tines of a fork, spread the caramelized onions over the crust, added the blue cheese, and sprinkled on the tarragon. It seemed to be heavy on the toppings to me, but having tasted the onions, I was ready to trust Nick’s judgment on this one.
I baked the tart in a 400˚F oven for about 20 minutes, until the crust was baked through and the cheese had melted and begun to brown. I probably should have let it bake for a few more minutes, as the crust was quite soft when I cut it.
I let the tart cool for about 5 minutes, then cut into it. It was so good — the buttery crust, the tang and sweetness of the onions, the bite of the blue cheese, and the sweet, licorice-like flavor of the tarragon, all complemented one another perfectly.
Nick bills this tart as an appetizer or first course, but I was perfectly happy eating it for a late-night snack and breakfast the next morning. It would pair well with a crisp, fruity wine.
As much as I’ve enjoyed the sweet puff pastry recipes that we’ve made over the past month or so, I have to say that this is among my favorite recipes in this section so far.