- 3 tablespoons unsalted butter
- 3 large onions, thinly sliced (about 8 cups)
- 2 1/2 teaspoons coarse salt
- 1/2 teaspoon freshly ground pepper
- 1/2 teaspoon sugar
- 1 bunch Swiss chard, leaves only, sliced crosswise 1 inch thick (about 5 cups)
- 16 ounces whole-milk ricotta cheese (2 cups)
- 2 large eggs, lightly beaten
- 5 (6 inch by 6 inch) lightly salted matzoh
- 1/2 pound fontina cheese, coarsely grated (about 2 1/2 cups)
Preheat oven to 375 degrees. In a large saute pan over medium-low heat, melt butter. Add onions, 1 teaspoon salt, 1/4 teaspoon pepper, and sugar. Cook, stirring occasionally, until golden brown and caramelized, about 30 minutes.
Add chard, and cook, scraping up browned bits from the bottom of the pan with a wooden spoon for about 10 seconds. Cover, and cook until chard is wilted, about 3 minutes. Remove from heat, and stir in ricotta, eggs, 1/2 teaspoon salt, and remaining 1/4 teaspoon pepper.
Meanwhile, place matzoh in a 9-by-13-inch baking dish. Cover with 6 cups water. Add remaining 1 teaspoon salt. Let stand until soft, about 2 minutes. Drain matzoh; dry baking dish.
In the same baking dish, arrange one-third of the drained matzoh in an even layer. It may be necessary to break some of the pieces for even coverage. Spread half the ricotta mixture evenly over the matzoh, and sprinkle with 1/4 cup Fontina. Repeat with remaining matzoh, ricotta mixture, and Fontina, finishing with a layer of matzoh. Sprinkle remaining 2 cups Fontina cheese evenly over the top. Bake until the cheese has melted and is beginning to brown, about 45 minutes.