Place chopped rhubarb a small bowl, drizzle in honey and pinch of sea salt and stir to ensure all pieces are well coated.
Place the rhubarb on a baking sheet and transfer to the oven for 8 minutes until rhubarb is tender but not too mushy.
While the rhubarb is cooking, make the dressing. Add olive oil, vinegar, mustard, honey and sea salt to a jar or bowl and whisk with a fork to combine.
Once the rhubarb is roasted, remove it from the oven, set it aside and allow it to cool slightly.
In a large salad bowl, combine the mixed greens, goat cheese and chopped walnuts, and top with roasted rhubarb.