Before starting, wash and dry all produce. Cut potatoes into 1-inch pieces. Add potatoes, 2 tsp salt and enough water to cover (by approx. 1 inch) to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat. Once boiling, reduce heat to medium. Simmer uncovered until fork-tender, 10-12 min. Drain and return potatoes to the same pot, off heat.

While potatoes cook, thinly slice mushrooms. Strip 1 tbsp thyme leaves from stems (dbl for 4 ppl). Roughly chop spinach. Peel, then cut half the onion into 1/2-inch pieces (whole onion for 4 ppl).

Pat chicken dry with paper towels, then cut each thigh in half. Season chicken with half the garlic salt and pepper. Heat a large non-stick pan over medium-high heat. When hot, add 1 tbsp butter (dbl for 4 ppl), then swirl the pan until melted, 1 min. Add chicken. Cook until golden-brown, 2-3 min per side. (NOTE: Chicken will finish cooking in step 4.)

Add mushrooms and onions to the pan with chicken. Cook, stirring occasionally, until veggies are tender-crisp and chicken is cooked through, 4-5 min.**

Sprinkle flour and thyme over chicken and veggies. Cook, stirring often, until coated, 1 min. Add 1 cup water (dbl for 4 ppl), broth concentrate and remaining garlic salt. Bring to a boil over high. Once boiling, reduce to medium. Cook, stirring occasionally, until sauce thickens slightly, 3-4 min. Add spinach. Stir until wilted, 1-2 min. Season with pepper, to taste.

Roughly mash 2 tbsp butter and 1/4 cup milk (dbl both for 4 ppl) into potatoes until slightly mashed. (NOTE: 'Smashed' potatoes will still have a few chunks!) Season with salt and pepper. Divide smashed potatoes between plates. Top with chicken, veggies and sauce from the pan.