How to Make It
Puree the tomatoes, onion, and garlic in a blender until smooth. Add the vinegar, 2 tablespoons of the oil, and ½ teaspoon each salt and pepper and pulse to combine.
Heat grill to medium. Once it is hot, clean the grill grate with a wire brush. Just before grilling, oil the grill grate.
Top 4 slices of the bread, dividing evenly, with the ricotta, herbs, and ½ teaspoon pepper. Sandwich with the remaining slices of bread. Drizzle the tops and bottoms of the sandwiches, dividing evenly, with the remaining 2 tablespoons of oil.
Grill until the bread is toasted and the cheese is warm, 2 to 3 minutes per side. Serve with the tomato soup.