This trip to Austin is our first AirBNB experience, and last night's dinner, cooked in our little apartment kitchen away from home, has convinced me this is a great way to travel. Hunting around in a new cooking space for measuring cups and rolling pins (oh, there isn't one? using my fingers!) or mixing bowls is kind of an adventure. And since we're in Austin, it's probably not surprising the kitchen came already stocked with coconut oil and organic popsicles. It was also fun to remake a pastry dough we've been making for years, but in a totally different place and with different tools. Note that our high-butter crust takes some getting used to in terms of preparation, but it rewards you with a totally flaky, delicious crust that is as good as the filling.
Preheat oven to 350F.
Prepare the spelt crust: Combine spelt flour and salt in a large bowl. Cut in butter quickly (using a pastry cutter or, when you're working with limited resources, your fingers), which basically means breaking up the chunks until they are about a quarter of their original size throughout. The mixture will still be crumbly and there may be some slightly large chunks; don't worry. Stir in the water. Now, using your clean hands, work the mixture into a ball of dough, pressing and smooshing it quickly with your hands. This will not take long and all you need to keep in mind is getting the dough into a ball as quickly as possible---what happens is your hands start melting more of the butter as you work the dough, which allows the mixture to soften a bit and come together, but you must do this quickly to avoid the dough becoming too soft. If, however, this does happen and the dough is sticking together, just add a little more flour. You control the dough. Once mixture is in a ball, wrap in plastic or set in a bowl and stick in the refrigerator.
Next, in a large saucepan or pot, melt the coconut oil over medium-low heat. Add the onions and stir them together with the oil. Let this mixture cook for about 20 minutes, or until the onions are soft and translucent and just starting to turn golden around the edges, stirring it once or twice. Once onions are ready, remove from stove to a separate bowl or plate.
Pull your ball of dough out of the oven and set on a floured surface. I placed mine right on the baking sheet after tossing flour on top; you could do this on parchment and then slide parchment onto your baking sheet if preferred. Press and flatten the dough into a rustic shape that's about 9 or 10 inches wide.
Top with Robusto cheese slices, then the prepared sauteed onion, then the whole Early Girl tomatoes, just plopping them right in the crust. Toss dried thyme all over the top and add a few shakes of salt (the tomatoes won't absorb the salt now, so they will stay sort of unsalted as they bake; the tart will be a little extra salted to make up for this, in part thanks to the cheese; together, the blend will be perfect!). Fold up the edges of the tart around the sides so you have a tart that is roughly 8 or 9 inches in diameter.
Place tart in oven and bake for about an hour, until crust is golden and tomatoes have wilted and burst. We ate ours in slices, alongside a giant salad.