Steam the butternut squash until barely tender, about 10 minutes. Remove half of the squash pieces and set aside.

Steam the remaining squash until very tender, an additional 4 to 6 minutes. Mash this squash with the back of a fork. Set aside.

In a large saucepan set over medium-high heat, bring the chicken broth to a simmer.

Add chicken thighs, cover, and cook until chicken is cooked through, about 15 minutes.

Transfer the chicken thighs to a plate and allow to cool. Pour broth into a medium-sized bowl.

Return the saucepan to the stovetop and lower heat to medium. Add olive oil.

Add onion and cook, stirring occasionally, until onion is starting to turn brown, 8 to 10 minutes.

Add the salt, minced garlic and oregano. Cook, stirring, for 1 additional minute.

To the saucepan, add tomatoes, butternut squash pieces, mashed butternut squash. Stir to combine.

Stir in reserved chicken broth and quinoa. Bring to a simmer, cover and cook until the quinoa turns translucent, about 15 minutes.

Shred the chicken with your fingers or a fork.

Stir the chicken, olives and pepper into the stew and simmer, uncovered, to heat, about 5 minutes.

Stir in parsley and serve.