Fill a pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the risoni and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through but is still firm to the bite, about 11 minutes. Drain well in a colander set in the sink.
Place the sun-dried tomatoes into the boiling water in a bowl and let stand for 10 minutes to plump up. Drain off excess water.
Toss the cooked risoni, sun-dried tomatoes, olive oil, lemon juice, lemon zest, olives, parsley and feta cheese together in a bowl. Season to taste with salt and pepper.