Grandma Ruth sets this down with a bag of napkins and suddenly everyone forgets they were “just having a bite.”

Add the chopped artichoke hearts, well-drained and squeezed spinach, minced garlic, onion powder, salt, black pepper, and crushed red pepper flakes (if using). Mix thoroughly, making sure the spinach and artichokes are evenly distributed and there are no big clumps.
Taste a small spoonful and adjust the seasoning with a pinch more salt or pepper if needed. Remember the cheeses are salty, so go slowly.
Divide the mixture evenly between the two prepared glass casserole dishes. Use the back of a spoon to spread the dip into an even layer with gentle swirls across the top.
Sprinkle the reserved 1/2 cup mozzarella cheese evenly over the tops of both dishes, letting some of the creamy mixture peek through so you’ll get pretty golden and creamy patches as it bakes.
Place the baking sheet with the dishes into the preheated oven. Bake for 20–25 minutes, or until the dip is hot and bubbling around the edges and the top is melted with golden-brown spots.
If you like a deeper golden top, move the dishes under the broiler for 1–2 minutes at the end, watching closely so the cheese doesn’t burn. You want a gently blistered, bubbly surface with creamy swirls still visible.
Carefully remove from the oven and let the dip rest on the butcher block or countertop for about 5–10 minutes. It will thicken slightly as it cools, making it perfect for scooping without sliding off your dippers.
Set the warm dishes in the center of the table or counter with a big bag of napkins and your favorite low-carb dippers. Serve straight from the glass dishes while still hot and bubbly.
Variations & Tips
For a little extra richness, you can swap half of the sour cream for heavy cream, though the dip will be slightly looser when very hot. If you like more tang, use plain full-fat Greek yogurt in place of some or all of the sour cream. Add 1/2 cup cooked, crumbled bacon or finely diced ham to turn this into a heartier, almost meal-like dip that feels right at home on a Sunday football table. For more flavor, stir in 1/4 cup finely chopped green onions or a tablespoon of dried minced onion. If you prefer a smoother texture, pulse the artichokes and spinach a few times in a food processor before mixing them in. To make this ahead, assemble the dip up through spreading it in the dishes, cover tightly, and refrigerate up to 24 hours; when ready to serve, bake straight from the fridge, adding 5–10 extra minutes to the baking time. Leftovers reheat nicely in a low oven or microwave and are excellent spooned over scrambled eggs or roasted vegetables for an easy low-carb breakfast or lunch.