In a hot saucepan, coat with oil and brown onions and garlic, about 5 minutes. Season. Add chicken stock and bring to a boil. The stock should taste salty, like pasta blanching water. Add the peas and cook until soft, about 5 to 8 minutes. Do not over-cook for they will darken. Check peas often. During the last minute, add the spinach. Immediately blend using a hand blender and when pureed, add the butter and blend well. Check for seasoning.
TRUFFLED SNOW PEA SALAD: In a bowl, whisk together juices and oils. Season with salt and pepper and check for seasoning. Toss well with snow peas.
PLATING Pre-heat the soup plates and ladle in the soup. Top with the salad and drizzle a little bit of truffle oil.