Preheat the oven to 400ºF/200ºC
Score the duck breast (skin-side only) and season both sides with salt and pepper
Add the duck breast skin-side down to an oven-safe skillet (DO NOT PRE-HEAT THE PAN), and heat it over medium-high heat.
When the fat begins to render, flip the duck breast and quickly sear the other side.
Turn the duck breast so that it's skin-side down again and pop it in the oven for 6-8 minutes.
While the duck is in the oven, add the vinaigrette ingredients into a jar
To test the duck for doneness, poke the centre with your finger. It should feel squishy, but springy, meaning it's pink on the inside. If you want to gauge this by temperature, duck is medium-rare at 135ºF/57ºC.
Once the duck is out of the oven, allow it to rest for 5 minutes before slicing. While the duck rests, assemble the arugula, tomatoes, cucumbers, carrot and avocado on plates.
Slice the duck on the diagonal. For best results, cut thick slices of duck so that it retains more heat.
Divide the duck between the plates, drizzle with vinaigrette and serve immediately.