1. Preheat the oven to 425 degrees F. Lightly grease a large baking sheet. In a bowl, combine the flour, polenta, baking powder, sugar and 1/2 teaspoon each of salt and pepper. Using 2 table knives, cut in the butter until the mixture resembles coarse meal. Add the cheddar, then stir in the milk until the dough is moistened.
2. Using 2 large soup spoons, scoop 8 mounds onto the baking sheet. Lightly press down on each mound. Bake the biscuits for about 19 minutes, until the tops are golden and the bottoms are browned. Transfer to a wire rack to cool slightly.
3. In a mini food processor, pulse the scallions, celery and jalapeno until finely chopped. Add the ham; pulse just until finely chopped. Pulse in the mayonnaise and mustard; season lightly with salt and pepper. Slice the biscuits; fill with the salad; serve.

Yield: 8 servings