With the weather up in the 80's in Tokyo this week, it really feels like we've blown through spring and headed straight into summer. To reassure my senses that the withering heat of summer is still a few weeks off, I picked up some springy green tomatoes at the local vegetable stand. Whether it's peaches, papaya or mangoes, I have a penchant for unripe fruit, and green tomatoes are no exception.
For me, unripe fruit isn't just a consequence of corporate farming, it's a unique ingredient with its own texture and unique flavor profile that can be delicious when properly prepared. It's also a fun challenge to come up with with new ways of using a familiar ingredient. I first made this green tomato gratin years ago when I still lived in New York, and and it's since become a favorite when these firm verdant jewels of spring are available in markets.
The rich mornay sauce provides the perfect contrast to the tart fragrant green tomatoes. When baked in the oven, the two meld together creating a well balanced side with a crisp, flavorful topping that goes beautifully with grilled meat. It also makes for a delightfully decadent breakfast when served with some poached eggs and toast.
- Put the oven rack in the middle position and preheat to 375 degrees F.
- To make the topping, mix the panko, onion powder, celery seeds, salt and pepper until everything is evenly distributed and then drizzle on the olive oil and stir to combine.
- To make the mornay sauce, put the butter and flour in a small saucepan and cook over medium heat until the mixture is bubbly, but do not let the flour brown.
- Turn the heat down and then whisk in the cream until the mixture is free of lumps and it starts to thicken.
- Once the sauce thickens, add the salt and stir in the cheese a little bit at a time until it is all incorporated. The mornay sauce will be very thick, but this is okay since the the tomatoes will release a lot of water.
- Arrange the sliced green tomatoes and mornay sauce in layers in an oven safe dish and then spread any remaining sauce on top of the green tomatoes.
- Sprinkle the panko topping evenly over the top of the tomatoes and then place the dish in the oven. Bake for 30-35 minutes or until the sauce is bubbling, the tomatoes are tender, and the breadcrumbs are golden brown.