In a medium-sized mixing bowl, whisk the lemon juice with the olive oil, garlic, sugar, mustard, chile paste and salt. Pour this into a large, zip-lock bag and add the Fioretto. (If the Fioretto isn't already in bite-sized pieces, you can slice the florets lengthwise, in half or in fourths.) Remove the air form the bag, seal it, and move the Fioretto around to be sure it's all well coated. Let it marinate in the refrigerator for at least 3 hours and up to overnight.