Preheat the oven to broil or 450F. Microwave the little potatoes in a ziploc bag (mostly closed) for 5 minutes, then toss with 2 tbsp olive oil and broil for 5 minutes. Alternatively, don't microwave the potatoes -- toss with olive oil, and roast for 20 minutes at 425F. Either way, the potatoes should be fully cooked and slightly browning.
Put the spinach in a large bowl. Pour the hot potatoes on top of the spinach and toss so the spinach starts to wilt.
Now, make the dressing. Add olive oil (1/4 cup), lemon juice, dijon mustard, maple syrup, garlic, salt, and pepper to a bowl. Whisk until smooth. Pour the dressing over the potatoes and spinach. Toss to combine.
Cut the dill and chives into small pieces. Add to the bowl and toss to combine. Enjoy the salad warm or cold!