12 ounces fresh spinach leaves
4 tablespoons (1/2 stick) unsalted butter
1 tablespoon finely chopped shallot (about one small shallot)
Pinch of sugar
Salt and freshly ground white pepper
3 large tomatoes, cored
2 tablespoons freshly grated Parmesan cheese
Preheat the over to 500 degrees.
Set a large bowl filled with water and ice cubes near the stove. In a large saucepan partly filled with lightly salted boiling water, cook the spinach for about 20 seconds or until just wilted. Stir well and then lift the spinach from the boiling water and immediately submerge in the ice water to stop the cooking. Lift the spinach from the ice water, let the spinach drain as much as possible, and squeeze dry. You will have about 2 cups of spinach.
In a medium saucepan, heat the butter over medium-low heat until bubbling. Add the shallot and cook for about 3 minutes, stirring, until softened. Add the spinach and sugar, season with salt and pepper and cook for about 1 minute or just until the spinach is hot and nicely coated with the butter and the shallot is evenly distributed. Set aside to cool.
Cut each tomato in half across the equator. Scoop out the seeds and center meat to make a "bowl". Cut a thin slice from the bottom of each half so each sits level on a rimmed baking sheet or shallow baking pan.
Season the tomatoes with salt and pepper and then divide the spinach evenly among the 6 halves. Sprinkle each with cheese.
Bake for 10 to 12 minutes or until the tomatoes are heated through and the cheese melts. Serve right away.