Warm spinach and tomato salad

Ohhhhhhh, this is so good. I could eat a huge bowl of this salad for dinner with nothing else, and be happy. This is a copycat of my favorite salad at Buca di Beppo. I found a few different versions online, and I played around with the quantities until I got something that tastes as good as the original. I think it is a great salad to go along with Italian food, a steak, chicken, or anything, really.

1/4 cup balsamic vinegar
1/4 cup olive oil
1 clove garlic, minced or pressed
1 tablespoon sugar
pinch of salt
1/2 small red onion, cut into strips
3 roma tomatoes, cut into wedges
5-6 ounces baby spinach
1/3 cup spiced or candied pecans, chopped
2 ounces crumbled goat cheese

In a small bowl, combing vinegar, garlic, sugar, and salt. Whisk in olive oil. Pour dressing in a saute' pan and add the onions. Heat on medium until it starts to simmer. Remove from heat and let dressing cool slightly. Put spinach and tomatoes in a large bowl or platter. Pour dressing and onions over spinach. Top with pecans and goat cheese. The flavor combination of the sweet pecans and onions, the tangy goat cheese and vinegar...mmmmmmmmm.

Note: The salad should really only be warm enough for it to not be cold...not enough that the spinach wilts. The first time I made it, the dressing was too hot when I poured it on the spinach, which instantly wilted and shriveled down to nothing. I ended up with spinach and dressing soup. So with the dressing, it is better to err on the side of too cool rather than too warm.