Preheat the oven to 425° F. Pour uncooked rice onto a baking sheet and shake rice into an even layer on the pan. Then, in a small saucepan over medium heat, melt 2 Tbsp. butter. Add in the yellow onion and sauté for 3-4 minutes, stirring occasionally. Add in minced garlic and stir for 30 seconds. Pour in chicken broth and season generously with salt. Bring broth to boil.
Once broth boils, pour broth over rice. Cover the sheet pan with foil and carefully place in the oven. Bake for 15 minutes.
For the chicken:
Sear chicken thighs in a frying pan on the stove over medium-high heat with olive oil or melted butter. Sear for 2-3 minutes on each side in until chicken slightly browns. (Don't worry, the chicken will cook all the way in the oven). Remove from heat and set aside in a medium sized bowl.
Whisk all of the ingredients together for the sauce: Dijon, maple syrup, rice vinegar, salt, pepper and rosemary. Reserve ~2/3 cup of the sauce. Pour remaining sauce over chicken and stir to coat.
For the veggies
Toss all of the chopped veggies in a large bowl with 1-2 Tbsp. olive oil and a pinch of salt and pepper.
Assemble the sheet pan meal:
Remove rice from oven and place the chicken on the rice and sprinkle the vegetables around the chicken.
Cover with foil again and bake for ~20 minutes (or until the chicken reads 165°F on a meat thermometer and the vegetables are fork tender.)
Rice on the edges will be a little crispy! Spread reserved sauce on chicken. Serve and enjoy!
If you don't like onions in your rice, simply boil the chicken broth and pour over the rice on the sheet pan. Season with salt so the rice has some flavor.
Searing the chicken is an optional step. Just know the chicken may take 5-10 minutes longer to cook in the oven.
Use other veggies you have on hand such as sweet potatoes, carrots, mushrooms, broccoli, Brussels, green beans, russet potatoes, or red onions.