After a green bean canning fiasco earlier this summer I said I was done with canning for the year. But then the cooler weather came, along with a great deal on bulk tomatoes, and it didn’t take long for me to change my mind. So this past weekend I not only canned a few dozen pounds of crushed tomatoes, but also slow roasted and dried some as well.

There are simpler ways to preserve tomatoes, though, such as freezing them whole and not having to go through the hassle of peeling and blanching. The same goes for peppers, too. Check out Radical Roots’ website for great tips on freezing. But until I get myself a chest freezer, that’s not the best option for me, as I can barely shut the freezer door as is.

But you could also just enjoy tomatoes now. It’s getting cold out, but a warm, flaky tart right out of the oven is a nice way to transition tomatoes into fall. If you have some heirloom tomatoes, they’ll make things especially attractive.


You can use your favorite pie crust recipe or find a quality one from the store. If you’re making your own, all you need to remember is the ratio 3-2-1. A basic crust is made from 3 parts flour, 2 parts butter and 1 part water. Add a little salt and/or sugar for flavor.

Cover the dough with Dijon mustard (a nice idea from David Lebovitz), top with a layer of sweet caramelized onions, plenty of cheese, then tomatoes and chopped fresh herbs. A drizzle of honey and balsamic vinegar add a nice touch to top it off.

Caramelized onions make everything better, so make sure to cook them long enough to get some good color – at least 20 minutes, but up to 45 minutes to an hour.

Crumble over the cheese – I like a sharp aged cheddar, but use what you like – Parmesan or goat would work well.


Then the tomatoes, herbs, honey and balsamic. Just pop it in the oven at 425 for about 30 minutes, or until the crust is crispy, the tomatoes tender and cheese melted. Serve along with a green salad.

Prep Time: 20 minutes

Cook Time: 30 minutes

Yield: 4-6 servings


  • 2 onions
  • 1 tablespoon olive oil
  • 12 ounces pie dough (your favorite recipe, or store bought)
  • 2 tablespoons Dijon mustard
  • 6 ounces cheddar cheese, sliced or chopped
  • 3 large ripe tomatoes, sliced
  • 2 tablespoons chopped fresh herbs, such as thyme, basil or chives
  • 1 tablespoon balsamic vinegar
  • 1 tablespoon honey (optional)


  1. Preheat the oven to 425°F.
  2. Slice the onions. Add to a medium pot with the olive oil set over medium-high heat. Cover and let cook about 25-45 minutes, stirring occasionally. Onions should be golden and sweet.
  3. Line a half sheet pan (18×13”) with parchment paper. Roll the dough out over top to fit the pan.
  4. Spread the mustard over the dough, then spread over the caramelized onions, the cheese, then tomatoes. Sprinkle over the herbs, balsamic vinegar and honey, if using.
  5. Bake 25-30 minutes until the dough is cooked and tomatoes tender.