Sauté the Aromatics: Heat 2 tablespoons of extra virgin olive oil in a large Dutch oven or heavy stockpot over medium heat. Add the diced onion, sliced carrots, and celery. Cook for 6 to 8 minutes, stirring occasionally, until the vegetables begin to soften and the onions turn translucent.
Add the Garlic: Stir the minced garlic into the pot and sauté for exactly 1 minute until highly fragrant, stirring constantly to prevent it from turning brown or bitter.
Brown the Chicken: Push the vegetables to the outer edges of the pot to create an open space in the center. Add the remaining 1 tablespoon of olive oil to that space, then add the diced chicken thighs. Season the chicken generously with sea salt and black pepper. Let it sear undisturbed for 3 to 4 minutes until golden brown on the edges, then stir to combine it completely with the vegetables.
Combine and Season: Stir in the cubed potatoes, the canned diced tomatoes with their juices, dried oregano, dried thyme, and smoked paprika. Pour the chicken broth over everything and drop the bay leaf right into the center. Stir gently to combine all the ingredients.
Simmer Until Tender: Bring the stew to a rolling boil over medium-high heat. As soon as it boils, immediately reduce the heat to low, cover the pot tightly with its lid, and let it simmer gently for 30 to 35 minutes. The stew is ready when the chicken is exceptionally tender and the potatoes are easily pierced with a fork.
Finish and Serve: Remove the pot from the heat source and discard the bay leaf. Stir in the fresh lemon juice and chopped parsley. Taste the broth carefully and adjust with an extra pinch of salt or pepper if desired. Ladle the hot stew into deep bowls and serve alongside rustic crusty bread.