Bring 1.5 cups of water to a boil over medium heat. Salt the water generously and add 1 cup of couscous. Cook couscous until it is done, according to time on package directions.
Drain the couscous and rinse thoroughly with cold water in order to cool and remove excess starch. If the couscous is clumping, mix a bit of oil into it.
Once the couscous has cooled, stir in the yogurt and lemon juice in a large bowl, as well as some salt and any other seasonings you want. Let it sit for a few minutes to absorb the yogurt.
At this time, cube your avocado and remove mint leaves from the stems.
Toss the arugula with the couscous until it is evenly combined. Toss in the avocado cubes as well, gently.
Sprinkle with salt, zest the lemon on top of the salad, and top with mint leaves. If you want more lemon flavor, add another squeeze to the top. Optionally, drizzle with a little bit of extra virgin olive oil.
Garnish with more zest and flaky salt. Serve chilled.