Thinly slice the ¾ of a seedless cucumber into rounds with a mandolin or knife, and transfer to a mixing bowl or serving tray. Peel and thinly slice the ½ sweet vidalia onion into half-moon shapes, and add it to the cucumber.
Trim the stalks and fronds away from the fennel bulb, and halve the bulb. Trim out any tough inner core. Then thinly slice one of the halves. Depending on the size of the fennel, you’ll need about ¼ of a large full bulb. Add the sliced fennel to the bowl.
Cut the drained 1/3 cup (packed) marinated artichokes into bite-sized pieces and add to the bowl.
Whisk together all of the Lemon Vinaigrette ingredients except the olive oil (juice of ½ lemon, 1 tsp. dijon mustard, 1 tsp. white wine vinegar, 1 tbsp. agave nectar, ¼ tsp. kosher salt, dash of garlic powder). Then whisk the dressing while slowly drizzling in the olive oil (1 tbsp. + 2 tsp. olive oil).
Finely chop the 1 tbsp. fresh dill and add it to the bowl with the vegetable mixture, then add most of the dressing. Toss gently and serve by topping with the diced avocado, lemon wedges, and salt and pepper to taste. Top with the remaining dressing as desired.