1 tablespoon olive oil
2 large onion, chopped
2 garlic cloves, minced
6 cups vegetable or chicken broth,
2 Yukon gold potatoes, peeled and cut into 1-inch pieces
1 bunch asparagus, cut into 1-inch pieces
3 cups chopped broccoli
Bring a large pot of salted water to a boil
Add broccoli and asparagus and cook till tender (about 5 minutes)
Remove the broccoli and asparagus, reserving one cup of the water
In the same pot, heat oil over medium heat. Sauté onion, garlic, and reserved water until fragrant (about 5 minutes). Cover with broth, add potatoes, and bring to a boil.
Reduce heat to medium-low and simmer gently until potatoes are tender, 15 to 20 minutes. Remove pot from heat ,add broccoli and asparagus and set aside to let cool slightly.
Carefully transfer soup to a blender (in batches) and purée until smooth. Ladle soup into bowls, garnish with sour cream or Parmesan cheese and serve. **this soup can be made with just asparagus or just broccoli