Gather all ingredients.

Preheat the oven to 375 degrees F (190 degrees C). Season chicken thighs evenly with salt and pepper on both sides.

Heat oil in a large oven-safe skillet over medium-high. Add chicken thighs to skillet, skin sides down, and cook until golden brown on both sides, about 8 minutes. Transfer chicken thighs to a plate; set aside. Do not wipe skillet clean.

Add tablespoon of olive oil or butter to the drippings. Add onion and cook, stirring often, until translucent, about 3 minutes. Add garlic and cook, stirring constantly, until fragrant, 30 seconds to 1 minute. Add rice, cream of chicken soup, lemon juice, lemon zest, tarragon, and crushed red pepper; whisk to combine. Add chopped veggies (if adding). Gradually add broth, whisking constantly, until combined and smooth. Arrange chicken thighs, skin sides up, over the rice mixture. For extra lemon flavor place lemon slices over chicken thighs (optional). Cover with aluminum foil or lid, and transfer to the preheated oven.

Bake in the preheated oven until rice is cooked through and a thermometer inserted into thickest portion of chicken registers 165 degrees F (73 degrees C), about 30 minutes.

Remove from the oven. Stir rice mixture, and sprinkle with parsley. Divide chicken, lemon slices, and rice evenly among 4 plates. Garnish with additional tarragon and crushed red pepper.