Heat oven to 375°F. Grease a 9x13-inch baking dish.
Boil noodles in salted water until barely al dente, 6–7 minutes. Drain.
Melt butter in a large skillet over medium heat. Soften onion for 4–5 minutes.
Stir in garlic and cook 30 seconds until fragrant.
Sprinkle in flour and cook 1 minute, stirring constantly.
Slowly whisk in milk and broth. Simmer, stirring, until thickened, 3–5 minutes.
Season with salt, pepper, paprika, and Dijon. Remove from heat. Stir in sour cream, then most cheeses.
Fold in ham, peas, and cooked noodles. Spread mixture into the prepared dish.
Toss panko with olive oil, parsley, and reserved cheese. Sprinkle evenly over the top.
Bake until bubbling and golden, 25–30 minutes. Rest 10 minutes before serving.