Start by preparing the baby artichokes. Leave baby artichoke whole, if small, or cut into halves or quarters. In large saucepan, over medium heat, bring vinegar, olive oil, salt to a simmer. Add prepared artichokes. Cover and simmer until tender (about 10 to 15 minutes). Drain well and set aside.

In small saucepan, broth until simmering; keep hot. Heat olive oil in a large saucepan over medium-high heat. Add onion and cook until translucent (about 3 minutes). Add rice. Cook and stir until all the rice is coated with oil and begins to turn golden (about 5 minutes).

Add 1/2 cup of hot broth. Continue to cook and stir until rice absorbs the broth. Continue to add broth, 1/2 cup at a time, cooking and stirring until each addition is absorbed. Set aside. In a skillet over high heat, sauté drained artichokes in olive oil stirring until artichokes begin to brown add garlic a minute before removing from heat.

Stir the cooked rice into the artichokes, then 2 cups broth. Bring to a boil and simmer until rice absorbs the broth. Stir in baby spinach and ¾ cup of Parmesan cheese, reserving ¼ cup Parmesan for the tops of mushrooms.

Preheat the oven to 375 F.

Line a sheet pan with parchment paper. Place the mushroom caps gill side up on the sheet pan with space between. Drizzle the caps with 2 tablespoons of olive oil. Season generously with salt and pepper.

Scoop approximately ½ cup hot risotto into each cap. Add two teaspoons of breadcrumbs followed by a teaspoon of reserved Parmesan cheese to the top of the risotto.

Bake the caps uncovered in the oven for 25-30 minutes, or until the tops are nicely golden brown and the mushrooms tender.