Strawberry and Spinach Salad with Balsamic Vinegar

Today at the Greenmarket, I was supposed to do a demo with asparagus. However, when I arrived, asparagus was going out, and spinach and strawberries were abundant. It was fun to have to change the according to what was in the market, which is what we should all do as shoppers/cooks.
Everyone loved the salad that I came up with, but since I did not have printed recipes, I told everyone to check back here later. Here is the general idea of what to do.

Spinach and Strawberry Salad with Balsamic Vinegar

1 bunch spinach, rinsed and long stems trimmed
1 handful strawberries, hulled and roughly chopped
1 sprig of mint
Few tablespoons of grated Queso Blanco*
¼ cup balsamic vinegar
Olive oil (optional)
Salt and pepper

Place the balsamic vinegar in a small saucepan over medium heat. Simmer until it is a bit syrupy and sweet. Remove from the heat and reserve.
In a large bowl, toss together the spinach and strawberries. Take about 4-5 of the mint leaves, finely slice, and toss into the bowl. Season with a pinch of salt and pepper.
Grate the cheese over the salad, pour over the balsamic vinegar (and oil if using), and toss.

* A nice sharp cheddar works well on this as well.
Serves 4.