Barbecue the pepper, onion and garlic and put aside the cool. Remove the skin of the opinion and the pepper then cut them into thin slices. Put them in a jar and chill until you’re ready to cook the pasta.
Cook the pasta according to the package instructions. Add the spinach leaves to the last minute of cooking, then drain.
Push the flesh of 3 grilled garlic cloves out of their skin into a big mixing bowl. Add the pesto and lemon juice, then mix well into a paste. ( Keep the rest of the garlic for other meals)
Add the drained pasta and spinach to the paste, then mix well to combine.
Slice the drained tomatoes into thin strips, add these to the pasta.
Add the onion and red pepper slices, together with their juices. Season to taste and toss well.
Tear the mozzarella into small pieces and scatter over the pasta.
Serve warm or at room temperature with some balsamic vinegar drizzled on top and plenty of freshly ground pepper.