Toasted pumpkin seeds are a must. Add some paprika or piri piri salt when toasting them to increase the yum.
I blend feta with Greek yoghurt and add to Roasted red pepper soup with the pumpkin seeds. It's a revelation.
Spray oil on drained chickpeas( I dry with a clean tea towel) and then roast in the oven or air fryer. These are good on salads or in cous cous,could be added to soups, as could the non-fried version.
Roasted Broccoli possibly in garlic or chilli oil.
Stilton and sour cream blended to a tasty dip drops nicely into Broccoli soup.
If not avoiding bread then toasted or baked/ crisp rounds of French stick with cheese put on them and toasted.
Croutons which I buy for caesar salad get used up in soups.
I also add toasted seed mixes and make my own dukkah to add to soups.
You could stir-fry cabbage and add (but I really love greens)
Or cook up some spinach and squeeze water out to add
Roasted asparagus is nice too. Doesn't take long to roast and you can bring the flavour out with a squeeze of lemon.
Roasted cherry tomatoes also good.
I just like adding texture to soups. I prefer a smooth soup with added something in the middle than a deliberately chunky soup.