Spicy cashew tomato soup

This is a real keeper - creamy, garlicky, with a memory of heat - perfect with the spinach rolls I made (too bad the rolls themselves weren't all that great). But we'll definitely be making this easy soup often. I found it here, and have added my few adjustments in italics.

Soup
1½ cups cashews, soaked in water for at least a few hours to aid processing
3 cups water or vegetable broth, to increase the vitamin quotient
1 can (28 ounces) whole peeled tomatoes or stewed tomatoes
1 tsp. cumin seed
1 tsp. fennel seed
1 tsp. coriander seed
1 serrano chile next time I'll try a couple of chipotles in adobo for variation - I usually have those around, though the serrano was very good, too.
1 Tbsp. olive oil
1 medium yellow onion, diced
3 stalks celery, diced
2 cloves garlic, minced
~ Juice of ½ lime or lemon I used 1 whole lime plus its zest
¼ tsp. salt
Optional seasonings and garnishes
~ Pinch or two of cayenne pepper
~ Curry powder
½ tsp. dried basil
½ tsp. dill I added a healthy Tb of this AND a pinch of curry powder - but I did so earlier
~ Chopped cilantro or Italian parsley leaves, for serving I skipped this
Steps

1. In a large bowl using an immersion blender, blend the cashews with the water. Blend or chop the whole tomatoes with their juices.
2. Grind the cumin, fennel, and coriander in a mortar and pestle or clean propeller grinder.
3. Mince the chile, being careful not to touch your eyes, mouth, or skin while doing so. (Use plastic or rubber gloves if you have them.) Discard the seeds inside the chile if you want less heat. Wash hands thoroughly when done. actually I put this in my food processor, then after it got pretty well pulverized, added onion. I realized too late that the pepper gets added to the soup later, but it worked really well anyway. I wanted to be sure the serrano got really well chopped up, because last time I used it, Mike and I both got little flame-bites un-uniformly through whatever dish I'd made. for some reason the serrano is harder to tolerate for me than other pepppers (like ghost chilies - we both love the heat!
4. In a stockpot, heat the oil and sauté the onion for a few minutes, then add the celery and continue cooking. When the celery has softened, add the garlic, chile, and spices. Cook another minute or two before adding the tomatoes and cashews. Simmer for 10 to 15 minutes, being careful not to burn the cashews on the bottom of the pot.
5. Add the lime or lemon juice along with the salt. Adjust the flavor, if desired, using some of the optional seasonings and garnishes. Serve with cilantro or parsley, if you wish.