For 80-100 crackers:
2 cups high grade flour
2 tsp baking powder
¼-½ cup finely grated Parmesan cheese
2 Tbs toasted sesame seeds
1 Tbs poppy seeds (optional)
½ cup bath-temperature water
1½ tsp flaky salt
1 tsp sugar
2 Tbs olive or avocado oil
about ¼ cup extra hot water
Heat oven to 160degC (150degC fanbake)
Measure the first five ingredients into a food processor or large bowl. Pour the first amount of hot water into a 1 cup measure, stir in the flaky salt & sugar until dissolved then add the oil. Process in bursts or toss the dry ingredients with a fork while you add the hot liquid mixture in a steady stream. Add as much of the remaining hot water as you need to form a ball of soft dough.
Cut the dough into four parts, & put three aside in a plastic bag. Roll out the other piece very thinly, using extra flour to stop it sticking, to make an oval shape larger than an A4 page. Cut in half (lengthwise), then cut each half into 10-12 tall thin triangles, like pennants, with alternate narrow bases & points on the cut edge.
Place triangles on a metal cake cooling rack, crumpling but not folding them. Bake them on the rack for 10-15 minutes, until pale gold but dry & very crisp. Lower heat & cook longer if necessary. Repeat with remaining pieces of dough. When cold store in airtight containers, reheating if crackers soften on storage.