Roast 'em now, you'll thank yourself later.
It's a conundrum. To describe my roasted tomato freezer sauce without waxing poetic would be an injustice. And yet, to do so risks putting off hesitant cooks instinctively mistrustful of gushy food writers. So let me just say this:
Roasting fresh summer tomatoes with a bit of olive oil, some fresh herbs and a fistful of garlic is a brilliant maneuver. Trust me. The tomatoes come out beautifully bronzed on the outside, with a concentrated, tomatoey flavor oozing from their softened innards.
The flavorful melange is a cross between a sauce and a filling. Chunky yet velvety. I pack each batch into freezer bags and am able to sustain a state of smug gratification for as long as my supply lasts. Usually into April. There are so many ways to use this special mixture - from a base for a quick pasta sauce and topping over roasted polenta, to omelette and lasagne fillings.
My friend Chris Peterson has been doing the same thing for several years; banking her flavorful cache in the freezer to maintain her summer-quality cooking all year long. And like me, she roasts her harvest until there is no more to harvest.
So by the end of the season, Chris figures she's squirreled away several gallons worth of sauce. Or filling. Or soup base. Or whatever you want to call it.
"I use the big square roasting pan that came with the oven," she says. "I spread a little olive oil on the bottom, cut tomatoes in half - slicer, paste (the best!) and cherries - whatever needs to be used up. I toss in a handful of peeled garlic cloves and some herbs (fresh rosemary, basil or cilantro), drizzle more olive oil over them, a little salt and pepper, and roast at 400 to 450 degrees for 20 to 30 minutes."
She goes more by sight than time, waiting until the tomato skins are turning blackish, "yet the rest is still juicy and the fragrance has our mouths watering."
In the Dominguez household, the roasting sometimes takes place out on our deck in my grill, over indirect heat, with the lid on. So even on the hottest days of summer, I can be roasting without heating up my kitchen.
Chris has created yet another option. It's a little time-consuming, she adds. But to anyone who has pondered whether to leave the tomato skins on or fish them out of the sauce before freezing it, she has a wonderful solution:
"After roasting, I pluck all the skins off (they peel off with ease) and put them in the blender or food processor along with some of the juicier liquid and most of the roasted garlic cloves, then whomp it up and pour it back into the pan with all the other stuff."
I've approached the skin issue from the other direction. Earlier this summer, I decided to find out if peeled tomatoes would roast up just as nicely as unpeeled tomatoes. Well, they do. The resulting mixture is just about as intensely flavored as the skins-on version, and produces a smoother sauce. Or topping. Or filling.
So while tomatoes and all the other savory offerings of summer are here, consider filling your freezer with a substantial supply. As Chris says, "Most anything that calls for tomato sauce will be boosted into outer space with roasted tomato sauce."
Variations and tips
There's a fun and free-wheeling aspect of preparing a batch of roasted vegetables for the freezer. Specific recipes aren't nearly as useful as listening to your inner cook.
For one thing, you can use any combination of tomatoes you're growing or find at the market, from beefsteak to Roma. The tomatoes themselves are going to guide you through the process: Some give off tons of juice during cooking, which means you need to roast them longer and you'll probably end up with a looser sauce. Others stay concentrated and tight, keeping their shape and just collapsing into their own intense flavor.
You can also slow-roast: I've seen recipes calling for a temperature as low as 250 degrees.
And don't be afraid to involve other vegetables beyond the basic onion-garlic scenario. For instance, one of my friend Chris' spinoffs involved eggplant. She had roasted a lot of it, "which leaves a horrid mess to scrape out of the pan," she adds. "But I decided to roast the tomatoes right away. The juice from the tomatoes worked all that flavorful black stuff up into the tomato sauce." It added depth and texture to her basic mixture.
To peel or not to peel? It's up to you. If you plan to puree the mixture once it's been roasted, then don't bother dealing with the tomato peels, because they will disappear once they've been subjected to the blender or food processor. Especially if you're using cherry tomatoes. With some of my batches I like to leave the vegetables in large chunks so I have more options for use in the months ahead. If I don't want pieces of peel in the mix it's easy to simply pluck them out of the sauce after thawing. They practically float away from the flesh.
Another wonderful combination is simply a roasting of whole garlic cloves (don't be shy! I use at least 2 cups worth) and tomatoes with a bit of olive oil, salt, and pepper of course. They both get tender and sweet in just about the same amount of time and can be used chunky as they come out of the oven, or pureed into a garlicky/tomatoey seasoner. Fresh herbs, such as basil, rosemary or oregano can also be included, but that will limit uses down the road.
Mushrooms make another great addition, but because they release a lot of moisture during cooking, I like to give them a 15-minute head start in the oven (or on the grill) before adding all of the other vegetables.
For an extra zip, add a bit of balsamic vinegar during roasting. It adds depth and oomph.
When I roast my tomatoes on a grill, I use a medium to medium-hot grill, covered. I have a wood pellet-fed grill (a Traeger, built in Mount Angel), which provides a wonderful smoky flavor to the vegetables.
Roasted Summer Tomatoes
Roasting fresh tomatoes until they're soft on the inside and beautifully browned on the outside concentrates their flavor. They come out of the oven gloriously golden and wrinkled and are wonderful gems to have on hand in the refrigerator and freezer for simple sauces and stocks over the days and months to come. I usually puree them into a velvety sauce right after roasting, but you can freeze them in their chunky state and decide what to do with them later in the year.
About 2 pounds tomatoes, peeled if desired (see note), cored and halved, quartered, or cut into 1-inch cubes (to measure 4 cups)
1 large Walla Walla Sweet onion, peeled and cut into 1-inch chunks
1/2 cup coarsely chopped basil
8 or 10 cloves of garlic, peeled
About 1/4 cup olive oil
About 1/2 teaspoon salt
About 1/4 teaspoon freshly ground black pepper
Prepare the tomatoes as desired. If using cherry tomatoes, simply remove the stems and halve each one. Place the tomatoes in a large roasting pan, jelly-roll pan or any baking sheet with sides. Add the onion, basil and garlic. You can crowd the vegetables together, but don't go beyond a single layer. Drizzle on a bit of olive oil, and then sprinkle with salt and pepper to taste.
Roast in a preheated 375- to 450-degree oven (the hotter the oven, the shorter the roasting time) until the tomatoes are turning a deep golden brown on their skins. Depending on your oven temperature, this will take anywhere from 20 minutes to about 90 minutes. When done, they will have collapsed and will look quite wrinkled. Alternatively, consider roasting the vegetables over indirect heat on your grill, with the lid on.
Remove the roasting pan from the oven or grill and let the vegetables cool. With a metal spatula or wide, flat-sided wooden spatula, stir and scrape the cooled tomatoes to dissolve all of the cooked-on bits of food.
Makes about 2 1/2 cups smooth sauce, 4 cups chunky sauce.
Jan Roberts-Dominguez is a food writer from Corvallis. She can be reached at firstname.lastname@example.org.