Cut the tops of the artichokes, about 1-2 inches from the top. Trim the stem. With scissors cut any pointy tips. Place in a pot of water, bring up to a boil and simmer for about 15-20 minutes until the artichokes are almost tender and the leaves pull off with a gentle tug. Rinse with cold water and set aside to cool.
Meanwhile, heat the olive oil in a small skillet. Add the onions and saute until wilted. Toss in the minced mushrooms and saute until tender. Remove from the heat, stir in the almond flour, ricotta cheese, beaten egg, salt & pepper.
When the artichokes are cool enough to handle, carefully open the center to expose the furry choke. With a spoon scrape out all of the hairs. If you remove several leaves in the process, no worries, you mostly just want the heart clean.
Preheat the oven to 400. Stuff the mushroom filling into the center, it can overlap a bit. Bake for 15-20 minutes, until the filling appears cooked. Sprinkle on a bit of grated parmesan if desired and bake for another 5 minutes until the cheese is golden.
Serve immediately while still hot.