In a large Dutch oven over medium-high heat, melt the butter. Add the onion, season lightly with salt and pepper, and cook, stirring occasionally, until softened and translucent, about 5 minutes. Add the celery and cook, stirring, until softened, about 5 minutes, adjusting the heat as necessary to avoid scorching. Stir in the garlic.

Pour in the wine and bring to a bubble. Add the stock and bring to a boil. Add the chicken thighs, lemon zest, parmesan rind (if used) and red-pepper flakes; season with 1 teaspoon salt and a generous amount of pepper. Mix well to combine all the ingredients and bring to a boil.

Remove rind (and enjoy with a slice of good bread). Add the frozen spinach and the artichoke hearts to the pot. Increase the heat to medium-high and cook, stirring to help the spinach defrost and wilt into the stew. When the spinach is warm and evenly distributed, reduce the heat and simmer until the chicken is tender and the flavors are blended, another 10 to 15 minutes. Remove from heat.

Add the lemon juice and the cream cheese, stirring to melt it into the soup. Add the dill. Taste and add more salt and black pepper if necessary.