Bring a large pot of salted water to a boil over high heat. Add the orzo and cook until tender but still firm to the bite, about 7 minutes.
While the pasta is cooking, heat 1/4 cup of the olive oil in a large saute pan over medium-low heat. Add the shallots and garlic, and saute until the shallots begin to soften and the garlic is fragrant, about 1 minute. Add the cherry tomatoes and cook just to warm through, about 1 minute.
Add the warm tomato mixture to a large bowl along with the feta, arugula, mint, balsamic vinegar, salt and pepper. Drain the orzo and add it to the bowl. Drizzle with the remaining 1/4 cup olive oil. Toss well and serve.