Place chicken thighs on a plate and pat dry with paper towels. Season the chicken with salt and pepper and flour.

Heat a large cast iron skillet over medium-high. Add 1 tablespoon of butter. Using tongs, add chicken in and cook, toss occasionally until fully cooked. Transfer chicken to a plate.

Reduce the heat to low and add the onion and garlic and season with salt and pepper. Cook, stirring often to dissolve browned bits on bottom of skillet, until onions are translucent, 6–8 minutes.

Add paprika and cayenne. Cook, stirring constantly, just until onions are evenly coated and spices are fragrant, about 30 seconds. Add tomatoes to skillet. Fill can two-thirds with water and swirl, then add to skillet. Stir until incorporated, seasoning with salt as you stir, and bring to a simmer. Simmer for 10 minutes. Using tongs, put the chicken along with any accumulated juices back into the skillet and simmer.

Cook the egg noodles according to package instructions, stirring occasionally. Drain noodles and transfer to a large bowl. Add the remaining 2 tablespoons of butter, and toss to coat until butter is melted and noodles are coated. Season with salt and pepper.

Finely chop ½ cup parsley and add half to noodles; toss to coat.

Taste sauce and season with salt and pepper as needed. Spoon in a spoonful of the sour cream and stir to combine. Continue adding the sour cream, little by little so it doesn’t curdle. Add the cooked pasta into the mixture and add the remaining parsley on top.