In the bowl of a food processor fitted with a steel blade, combine the mustard paste, salt pepper. Pulse the mixture together briefly. Then add the vinegar a little at a time. While continuing to pulse, add the olive oil in a very patient, slow, steady stream to produce a smooth, creamy, mayonnaise-like emulsion. At this point, the dressing can be refrigerated for up to 1 week. When ready to serve, stir in the chili sauce, watercress, and bacon to complete the classic "21" Lorenzo Dressing.
Put the remaining salad ingredients in a large bowl and toss with the dressing.