Even when I was a little boy I was a champion of diversity.   I didn’t care if the onion was white, yellow or red.  I liked them all.

My favorite meal at grandma’s house was the onion sandwich… thin slices of onion, two slices of bread, and a generous layer of Duke’s mayonnaise.

Fortunately for all of you, my tastes are a little more sophisticated now, but sophisticated and simple are not mutually exclusive when it comes to good recipes.

Have you ever thought about combining savory caramelized onions, tangy bleu cheese and sweet, juicy slices of apple?   I hadn’t either until Sandy Gluck made the suggestion.

The result was a delicious and decadent onion tart that will impress every single person at your table.

6 tablespoons  olive oil

21/2 pounds yellow  onions, halved and thinly sliced

1 large sweet apple, peeled and cut into thin wedges

Coarse salt

All-purpose flour

3/4 pound storebought or homemade pizza dough

8 ounces blue cheese, crumbled

1/3  cup walnuts, coarsely chopped

In a large skillet, heat 4 tablespoons of  the oil over low heat. Add the onions, cover the skillet and cook,  stirring occasionally until the onions are tender, about 25 minutes. Uncover and continue cooking, stirring frequently until the onions are golden brown, about 20 minutes more. Stir in the apple, season with salt and cook until crisp-tender, about 5 minutes longer.

Preheat the oven to 500. On a lightly floured work surface, roll the dough out to a 14 inch round. Transfer the dough to a large baking sheet and brush the top with the remaining  2 tablespoons oil. Scatter the caramelized onion-apple mixture over the top, leaving a 1-inch border all around. Scatter the cheese and nuts on top. Bake on the lowest rack in the oven until the crust is crisp and the cheese has melted, 12 to  15 minutes.