1. Preheat oven to 425°.
2. Combine tomatoes, 1 teaspoon oil, thyme, and garlic on a foil-lined jelly-roll pan. Roast at 425° for 17 minutes.
3. Combine honey, cider vinegar, and mustard in a bowl, stirring with a whisk. Heat a large skillet over medium-high heat. Add remaining 2 teaspoons oil to pan; swirl to coat. Sprinkle pork evenly with salt and pepper. Add pork to pan; cook 3 minutes on each side or until desired degree of doneness. Remove pork from pan. Add stock to pan; cook 2 minutes or until reduced by half. Remove pan from heat; stir in honey mixture.
4. Place tomatoes, spinach, and balsamic vinegar in a bowl; toss to coat. Serve salad with pork and sauce.