First, roast the peppers: cut the tops of the bell peppers off; discard seeds and membranes. Then, slice the peppers in half and flatten with the palm of your hand. Roast peppers on BBQ (or oven set to broil) until black, remove and place in a large bowl; cover with saran wrap. Let sit for 15 minutes. Peel off blackened skins and chop.
Heat olive oil in a large pot over medium heat. Add onions, garlic, thyme, and oregano. Saute, stirring occasionally until the onions begin to soften and look translucent, about 5 minutes.
Add potato, bell peppers, broth, and tomatoes. Bring to a boil, cover and reduce heat to simmer until the potatoes are very tender, about 30 minutes.
Using an immersion hand blender or stand blender, puree the soup until it is very smooth. Add lemon juice, salt and pepper. Adjust seasonings to taste.
Ladle into bowls and serve hot with fresh snipped chives for garnish