Peel the sweet potato and cut into cubes. Toss the sweet potatoes with olive oil, salt, and pepper, and spread onto the baking sheet. Roast for 15 minutes or until golden brown. Remove the roasted sweet potatoes from the oven, set aside, and cool down.
Thinly slice the radish into rounds and place in ice water for 5 minutes. Cut the avocado in half, remove the stone and the skin, and cut into slices. Toss the avocado slices with a squeeze of lemon. Set aside.