Vegetable Stew

I decided to make this vegetable stew for something hearty without animal protein.  It was just okay, but maybe just a little too much kale for me, and I think I'd use more flavorful chicken broth instead of vegetable broth in the future. I felt like it needed more seasoning.
 
Vegetable Stew
Yield: 8 bowls

Ingredients:
2 tablespoons olive oil
1 large yellow onion, diced
4 ribs celery, chopped
4 carrots, chopped
2 cloves garlic, minced
1 can white beans, drained and rinsed
1 can black beans, drained and rinsed
1 bay leaf
2 or 3 quarts vegetable stock
2 cups Brussels sprouts, stems removed and cut in 1/2
2 bunches of kale  and/or collard greens, stems removed and chopped
1 large sprig rosemary
salt and pepper to taste

Directions:
In a large soup pot over medium heat, heat oil.  Add onion and celery, and stir and cook for 2 minutes.  Add carrots and cook for another 5 minutes, stirring occasionally.  Add garlic, beans, and bay leaf, and stir for 1 minute.  Add vegetable stock until it covers veggies by an inch.  Bring to a boil.  Add Brussels sprouts and kale, along with more stock if necessary, and bring to a boil.  Reduce heat to low and simmer for 10 minutes.  Remove pot from heat, add rosemary, cover, and let sit for 15 minutes.  Remove rosemary and bay leaf, add salt and pepper to taste, and serve.