In a large skillet, cook the bacon over medium-high heat until crisp, about 5 minutes. Drain on paper towels and pour off all but 1/4 cup of grease from the pan.

To the fat in the pan, add the onions and cook, stirring, over medium-high heat until soft, about 3 minutes. Add the garlic, pepper, and salt and cook, stirring, for 30 seconds. Add the mustard and vinegar and cook, stirring to deglaze the pan. Add the sugar and stir to dissolve. Add the cherries and cook, stirring, until slightly plumped and warmed through, about 1 minute. Remove from the heat and whisk in the oil. Return the bacon to the pan and adjust the seasoning, to taste.

In a large bowl, toss the spinach with the warm dressing. Divide the salad among 4 salad plates, arrange the orange segments around the edges, crumble the goat cheese over the top and serve.