Line a 11″ x 17″ baking sheet completely with foil (making sure it goes up the sides) and preheat the oven to 350F degrees.
Line the bottom of the sheet completely with matzoh, breaking extra pieces as necessary to fill in any spaces.
In a medium-sized heavy duty saucepan, combine the butter and brown sugar and cook over medium heat until the butter begins to boil. Boil for 3 minutes, stirring occasionally.
Remove from heat and pour over matzoh, spreading with a heatproof utensil.
Put the baking sheet in the oven and bake for 15-20 minutes, until the syrup darkens and gets thick. (While it’s baking, make sure it’s not burning. If so, reduce the heat to 325F degrees.)
Remove from oven and immediately cover with chocolate chips or chunks. Let stand 5 minutes, then spread smooth with an offset spatula.
Sprinkle with a flurry of fleur de sel or coarse salt, then scatter the toasted almonds over the top and press them into the chocolate.
Let cool completely (you may need to chill it in the refrigerator), then break into pieces and store in an airtight container until ready to eat.