Cook the quinoa according to the package directions and let cool.
In a small jar with a lid, combine the lime juice, olive oil, maple syrup, and mustard. Cover and shake until mixed well. Taste for seasoning and add salt and pepper as needed.
Toss the strawberries, avocados, cooked quinoa, walnuts, feta, and arugula together in a large bowl. Add the dressing and toss again. Serve.
