Slice the tomatoes into ½ inch thick slices and transfer to a large bowl Set aside.
Combine the garlic and vinegar together in a medium bowl and let stand for 10 minutes. Add the salt, sugar, pepper, mustard and parsley and whisk together. Slowly whisk in olive oil. Pour the vinaigrette over the tomatoes. Let stand at least 30 minutes, gently turning over occasionally. Serve at room temperature.
Use a serrated knife to cut the tomatoes. Slicing ripe tomatoes with a regular knife isn't easy. Switch it out for one with a serrated edge (one with visible teeth like a bread knife) instead. You will get much cleaner slices!
Calories: 247kcal | Carbohydrates: 1g | Protein: 1g | Fat: 27g | Saturated Fat: 4g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 20g | Sodium: 613mg | Potassium: 25mg | Fiber: 1g | Sugar: 1g | Vitamin A: 318IU | Vitamin C: 5mg | Calcium: 8mg | Iron: 1mg