Whisk 100 g buckwheat flour, 200 g 00 flour, and 1/2 tsp fine salt on a clean counter and make a well in the center. Add the egg and 80 ml warm water, stir with a fork until shaggy, then knead for 8 to 10 minutes until firm and smooth. The dough feels dry and slightly crumbly at first because buckwheat absorbs water slowly, so don't add more water yet.

Wrap the dough tightly and rest it at room temperature for 30 minutes. Press it with a finger afterward. If it cracks, knead in 1 tsp warm water at a time until it feels smooth.

Cut the dough into 4 pieces and keep the others covered. Roll one piece on a lightly floured counter to a rectangle about 15 x 30 cm and 2 mm thick. Cut it into 4 cm squares with a knife or pizza wheel, then cut each square in half diagonally into 2 triangles. Repeat with the other pieces and re-roll the trimmings once.

Dust two 33 x 46 cm / 13 x 18 inch sheet pans with semolina. Spread the triangles in a single layer and separate any that touch. You'll have about 160 to 200 triangles.

Bring 4 L of water to a boil in a 6-quart / 5.7 L pot and add 2 tbsp coarse salt. While it heats, melt 80 g butter in a 30 cm / 12-inch skillet over medium heat. Add 12 sage leaves and cook for 2 to 3 minutes until the butter foams, turns pale gold, and smells nutty and the leaves crisp. Take the skillet off the heat.

Add the triangles to the boiling water and stir gently once. Cook for 3 to 4 minutes, until they float and are tender with a slight chew. Scoop out 120 ml of the pasta water, then lift the triangles out with a spider.

Add the triangles to the skillet with 60 ml of the pasta water and set it over medium-low heat. Toss for 30 to 40 seconds until the butter coats each piece, adding a spoonful more water if it looks tight. Stir in half of the 50 g smoked ricotta, divide among warm bowls, and top with the remaining ricotta and black pepper.