Francesco calls these sour potatoes – in Venetian, patate all’agro. Something is lost in translation. In the Veneto the notion of a “sour” flavor has none of the negative connotations that it does in English. In fact, it implies a taste that is lively, appealing, and appetite-whetting. These “sour potatoes,” or mustard potatoes as they are called at Remi, are a delicious addition to a cold summer buffet. The sauce is like a mayonnaise, made with raw egg yolks. When organic or farm eggs are used, the yolks should be safe to eat raw. If you have any doubt you can substitute 1.5 cups (375 g) commercial mayonnaise thinned with the tarragon vinegar and stock and seasoned with the mustard and red onions.
- 3 baking potatoes
- 2 tbsp (30 g) Dijon mustard
- 2 raw egg yolks
- 2 tbsp (30 ml) tarragon vinegar
- Pinch of salt
- 1 1/2 cup (375 ml) very finely chopped red onion
- 1/3 cup (80 ml) vegetable stock or water
- 1 tbsp chopped flat-leaf Italian parsley
- Steam the potatoes in their skins until they are tender, about 40 minutes.
- Peel and slice them 1/4 inch (6 mm) thick.
- Place the slices in a single layer on a baking sheet or one or more platters.
- Combine the mustard, egg yolks, vinegar and salt in a food processor and process until blender.
- With the machine running, slowly add the oil through the feed tube and process until the mixture is thick.
- Stir in the onion and the stock or water and beat until smooth.
- Pour the dressing over the potatoes and allow to marinate 1/2 hour.
- Sprinkle with parsley before serving.