Heat butter in a large pot over medium heat and add diced carrots, onions, and celery. Sauté the veggies in the butter for 5-7 minutes, tossing frequently
While the veggies cook, peel and cut the potatoes into 1" cubes and zest two lemons before squeezing them for 1/4 cup lemon juice
Add oregano, dill, garlic, salt, and pepper to the pot and sauté for another minute.
Add the chicken broth, water, chicken breast, lemon juice, and potatoes to the pot. Give the soup a gentle stir and increase the heat to high
Allow the soup to come to a boil, cover and reduce to a simmer. Allow the soup to simmer covered for 20 minutes and turn the heat all the way to low before removing the chicken breasts
Shred the chicken breasts and pour back into the pot along with the lemon zest from earlier. Stir to combine and serve soup warm with fresh lemon, fresh dill and black pepper.
Notes
To Make in the Instant Pot
Turn instant pot on to sautee, melt butter and sautee carrots, celery and onion.
Add cubed potatoes, chicken breast, lemon juice, chicken broth and water to the instant pot and stir
Set the vent to sealing and set the Instant Pot to manual high pressure for 15 minutes
When IP is done, release pressure manually, shred chicken, stir in shredded chicken and lemon zest and serve
Freezing instructions: Let the soup cool completely and store in airtight containers in the freezer for up to 3 months. Thaw overnight in the fridge and reheat on the stove or reheat directly from forzen. If the potatoes get slightly soft after freezing, that is normal.
Make it avgolemono-style: To add the traditional egg-lemon sauce, whisk 2 egg yolks with 3 tablespoons of lemon juice in a bowl. Ladle a cup of hot broth into the egg mixture slowly while whisking to temper it. Then pour the mixture back into the pot and stir. Do not boil the soup after adding the eggs or they will scramble.
Use rotisserie chicken: To save time, use the shredded breast meat from a store-bought rotisserie chicken. Stir it in at the end of cooking instead of adding raw chicken to the pot.