This simple recipe can be made ahead of you.
- First make the vinaigrette. Preheat the oven to 220 ° C / Gas 9.
- Place the onions in a roasting tray with a little olive oil, the thyme, garlic and a little salt and roast for 25-30 minutes until the onions are completely cooked and have a nice roasted flavour.
- Remove the onions from the tray and chop into rough dice (you want the dressing to have a rustic texture).
- Mix the onions with the 150ml extra virgin olive oil and the sherry vinegar and season with a little salt and pepper to taste.
- To make the salad, blanch the beans by plunging them in boiling salted water for 1½ minutes until their rawness has been removed but they are still crunchy. Refresh immediately in cold water, then remove and put onto kitchen paper to absorb the moisture. Cut each bean into bite-sized pieces.
- Put the chopped beans into a large bowl, stir in the red onion dressing, and toss with the parsley and mint. Serve immediately in chilled salad bowls.