Boil potatoes in salted water until fork-tender, about 15 minutes. Drain, mash with milk and sour cream; keep warm.
Season tenders with salt and pepper. Dredge in flour, dip in eggs, coat with panko.
Heat olive oil in a skillet over medium-high. Cook tenders 3–4 minutes per side until golden and cooked through.
Reduce heat, add butter and garlic to pan. Spoon garlic-butter over tenders for 30 seconds.
Serve tenders over mashed potatoes and sprinkle parsley. My kids love when I drizzle extra butter over the mash.