Preheat the oven to 375°F. Lightly grease (or line with parchment) two baking sheets., In a large bowl, beat together the butter, shortening, sugar, tomato paste, cheese, herbs, baking powder, and salt until smooth. Add the eggs, one at a time, mixing until each is absorbed before adding the next. Scrape down the bowl, then add the flour. Mix until the dough is cohesive. Stir in the nuts., Divide the dough in thirds. Shape each third into a 10" log and place on the prepared baking sheets, leaving at least 3" between them. Wet your fingers and pat the logs into smooth rectangles 10" long and 2 1/2" wide., Bake the logs for 20 to 25 minutes, until the edges begin to brown. Remove from the oven and let cool for 30 minutes. Lower the oven temperature to 300°F., Transfer the logs to a cutting board and spray or brush lightly with water. Use a serrated knife to cut into 1/2"-wide slices. Don’t press down on the knife; rather, draw it back and forth in a sawing motion until the slices are cut, to keep crumbling to a minimum., Return the slices to the baking sheet, standing up with 1/2" of space between them. Return to the oven and bake for 35 to 40 minutes, until very dry and lightly browned. Remove from the oven and let cool on the pan. Store in an airtight container.