How to Make It
Preheat oven to 450°F. Combine zucchini and 1 teaspoon salt in a colander; let stand until ready to use.
Combine pepper and remaining 1 teaspoon salt; sprinkle evenly over both sides of chicken thighs. Heat a 10-inch ovenproof skillet or sauté pan over medium. Add oil to pan; swirl to coat. Add chicken to pan, skin side down. Cook until skin is browned and crisp, about 10 minutes. Flip chicken thighs; cook 6 minutes. Remove chicken from pan (chicken will not be fully cooked).
Add onion, garlic, and thyme to drippings in pan. Cook over medium, stirring occasionally and scraping any browned bits from bottom of pan, until onion is crisp-tender, about 5 minutes.
Drain zucchini on several layers of paper towels; squeeze gently to remove excess moisture. Add zucchini to onion mixture in pan; toss with tongs to combine. Nestle chicken into zucchini mixture. Place pan in preheated oven; cook until a thermometer inserted in thickest part of chicken registers 165°F, 13 to 15 minutes. Serve chicken and zucchini over quinoa; garnish with thyme, if desired.