Note: I made a few changes here, notably moving from Gruyere to parmesan which I feel aligns better with the underlying basil pesto flavor.
- 8 ripe plum tomatoes cored (other types of tomatoes like beef steak can be substituted)
- 3/4 cups parmesan for filling
- 1/4 cup parmesan for topping
- 1 1/2 cups fresh basil leaves
- 1/3 cup extra virgin olive oil
- 1/4 cup gluten free panko bread crumbs or gluten free italian breadcrumbs (GF panko is hard to find; the italian ones work just fine)
- 1 clove minced garlic
- Salt and Pepper
Using a serrated knife, cut a thin slice from the bottom of the tomatoes so they can sit flat. Save the slices so they can be topped with the leftover pesto at the end. Once the tomatoes can sit flat, cut vertical slices in them separated by 1/4” intervals.
Setup a baking sheet with a wire rack over it (and tin foil underneath the rack). Put the tomatoes on the rack.
Add to the food processor, 3/4 cup parmesan, oil, basil, bread crumbs, garlic, 1/2 tsp salt and 1/2 tsp pepper and process until smooth, about 10 seconds.
Turn on broiler and set to high with the rack 6” below the heat element.
Fill tomatoes in the cored hole with the pesto filling and then place some inside each of the slices. Add remaining pesto to slices. Sprinkle remaining 1/4 cup parmesan on top of the tomatoes and slices.
Broil for 4 to 5 minutes until cheese is browned and tomatoes are cooked.