Named for the hotel where it was invented in Sweden, Hasselbacking is a technique where a vegetable (traditionally potatoes) is partially sliced, accordion style, brushed with butter, sprinkled with bread crumbs, and baked.
This approach is also great for tomatoes; think of them as levelled-up stuffed tomatoes featuring tons of crispy edges and great browning. We started with meaty, well-shaped plum tomatoes.
We cored them, then cut into them and spread a potent, flavourful homemade basil pesto mixed with some crunchy panko bread crumbs over the interiors.
We then topped the tomatoes with shredded Gruyere cheese for added punch and placed the stuffed tomatoes under the broiler for just 5 minutes to melt the cheese and slightly soften the tomatoes without turning them to mush.
For the best results, we recommend buying ripe tomatoes of similar weight and size. We developed this recipe with tomatoes that averaged 3 ounces in weight and 2 1/2 inches in length.
Start to finish: 45 minutes
8 ripe plum tomatoes, cored
7 ounces Gruyere cheese, shredded (1 3/4 cups)
1 1/2 cups fresh basil leaves
6 tablespoons extra-virgin olive oil
1/4 cup panko bread crumbs
1 garlic clove, minced
Salt and pepper
Line rimmed baking sheet with aluminum foil and set wire rack in sheet. Using serrated knife, cut 1/4 inch-thick slice from 1 long side of each tomato to create a flat base. Turn tomatoes onto cut sides so they sit flat, then slice crosswise at 1/4 inch intervals, leaving bottom 1/4 inch of each tomato intact.
Process 3/4 cup Gruy√®re, basil, oil, panko, garlic, 1/2 teaspoon salt, and 1/2 teaspoon pepper in food processor until smooth, scraping down sides of bowl with rubber spatula as needed, about 10 seconds.
Adjust oven rack 6 inches from broiler element and heat broiler. Combine 3/4 teaspoon salt and 3/4 teaspoon pepper in bowl. Carefully open tomato slices and sprinkle with salt-pepper mixture. Using small spoon, spread basil mixture evenly between tomato slices (about 2 tablespoons per tomato).
Arrange tomatoes on prepared wire rack. Sprinkle remaining 1 cup Gruy√®re over tomatoes. Broil until cheese is golden brown, about 5 minutes. Serve.