Separate the florets of broccoli and finely chop them. Trim away any stringy skin from the stalk and finely chop. Alternatively, you can separate the florets, trim and slice the stalk and pulse the broccoli in a food processor until chopped.
Heat 1 tablespoon of olive oil in a pot over medium-heat and then saute the onions until they are very fragrant and just starting to turn brown. Don't caramelize them all the way or your soup will turn brown.
Add the broccoli and saute until bright green, about 2 minutes.
Add the vegetable stock, raw cashew nuts, nutritional yeast, and salt and bring the soup to a boil over high heat. Cook for 3 minutes.
Transfer the soup to a blender and puree until smooth.
To make the garlic seed oil, add the olive oil and garlic to a small frying pan and fry until the garlic is light brown.
Add the walnuts, pumpkin seeds, chia seeds, and nigella seeds and season with a pinch of salt.
Toast the nuts and seeds until fragrant and just starting to brown (about 1-2 minutes). Be careful not to burn the smaller seeds.
To serve the broccoli cheese soup, reheat it and ladle it into bowls. Top with a smattering of nuts, seeds, and oil.