Drain tuna, flake with a fork, and place in large salad bowl. Drain and rinse beans and add to the bowl.

Wash and dry chard and stack leaves together. Roll into a tight log, and slice very thinly (the fancy term is chiffonade). Add chard to the bowl.

Carefully cut the rind (including the white pith) away from the flesh of the orange. Using your knife, cut each segment free from the membrane that separates them (the fancy term for this is supreme). Do this over a bowl to collect any orange juice that drips (which will be used in the dressing). Place the oranges in the salad bowl and set the juice aside.

Cut the fronds off the top of the fennel bulb and set aside. Cut the base from the fennel. Slice fennel very thinly using a sharp knife or a mandoline. Add fennel to the salad bowl.

Slice the kalamata olives in half, and add to the salad bowl, along with the red onion.

Finely mince some fennel fronds until you have about 1 tablespoon and add to the salad bowl, along with the mint and parsley.

Add the lemon juice to the bowl of reserved orange juice. Finely mince the garlic (or grate using a microplane) and add to the juice. Whisk in Dijon mustard. Slowly drizzle in the olive oil, whisking until combined. Add salt and pepper to taste.

Drizzle half of the dressing over the salad and toss well so that everything is evenly combined. Taste and add more dressing or salt and pepper, if necessary. Serve immediately.