A great dipping sauce or all purpose condiment from ” Season” by Nik Sharma. It will keep for up to a month in an airtight container in the fridge.
Preheat the oven to 250°F [110°C].
While the oven is heating, fill a medium saucepan with water and bring to a rolling boil. Fill a medium bowl with ice water. Using a paring knife, trim both ends of the pearl onions and plunge the onions into the boiling water for 30 seconds.
Using a slotted spoon, transfer to the ice water to stop the cooking. Drain and put the onions on a clean kitchen towel or paper towels and dab dry. Using the paring knife, remove the skins and halve the onions lengthwise.
Cut the rhubarb crosswise into 1 in [2.5 cm] pieces. In a medium bowl, combine the rhubarb, onions, chiles, makrut lime leaves, and salt. Add the olive oil and toss to combine.
Transfer to a shallow baking dish and bake until the rhubarb chunks are tender and almost mushy, about 3 hours. Remove the dish from the oven and cool completely.
Transfer the confit to an airtight container and refrigerate for up to 1 month.