Sprinkle the yeast into the work bowl of a food processor with the steel mixing blade attached. Add the warm water and stir with a spoon to dissolve. Add the ice water, olive oil, 2 cups of bread flour (250g) and the salt. Pulse until combined well. Gradually add more flour, up to 3 cups (375g) pulsing between additions. Process for about 2 minutes.

Turn the dough out onto a heavily floured surface and knead by hand for about 1 minute. Grease a large clean bowl with olive oil, and place the dough in the bowl, turning once or twice until the dough is coated with oil. Cover with a clean towel and allow the dough to rise until doubled in bulk, about 1 hour.

Punch down the dough. Meanwhile, line a half sheet pan (18”x13”x1”/ 43cm x 31cmx2.5cm) with parchment paper. Turn the dough out onto the pan and press out into a large rectangle. Brush liberally with olive oil and allow to rise for about 30 minutes. Preheat oven to 400°F (204°C).

Sprinkle over with shredded cheese and jalapeño slices. Bake for 20-25 minutes until golden brown.