To make candied walnuts, heat a skillet over medium heat and briefly toast walnuts until they begin to color, stirring frequently so they do not burn. Sprinkle the walnuts with half the sugar, and stir until the sugar has melted. Sprinkle with salt, pepper and remaining sugar, and continue stirring. The pepper will smoke, so make sure your exhaust fan is on. Continue stirring until all the sugar has melted. Remove from heat and spread out on a sheet of tinfoil, making sure all the walnuts are separated. Allow to cool.
To make the dressing, put the shallots, vinegars and honey in a small bowl and whisk to combine. Slowly whisk in the olive oil to form an emulsion. Season with salt and pepper to taste.
Build the salad in a wide shallow bowl. Spread the lettuces over the bottom of the bowl. Arrange the strawberries, berries, chicken, dates, candied walnuts and feta over the lettuce. Toss with dressing and serve.