Combine vinegar, minced garlic, basil, salt, and pepper in a bowl. Whisk to combine while slowly adding olive oil.
Cook orzo in salted water according to package instructions.
Meanwhile, halve tomatoes, slice green onions, and roughly chop spinach; place in a large bowl.
Drain orzo and immediately add to bowl with the veggies and toss. (The heat from the orzo will lightly wilt the spinach.)
Pour the dressing on top and toss to combine. Carefully stir in feta and almonds.
Serve immediately, or refrigerate for 1-2 hours and serve chilled.
Serve with tangerines on the side.