Adjust rack to middle position and preheat oven to 400 degrees. Peel and quarter shallots, then place on a large piece of aluminum foil. Lift sides of foil and crimp to make a bowl. Toss in vinegar, a drizzle of olive oil, and a pinch of salt and pepper. Place on a baking sheet. Roast in oven until shallots are soft, 15-20 minutes.

Wash and dry all produce. Bring 3 cups water and stock concentrates to a gentle simmer in a small pot. Mince or grate garlic. Halve lemon. Using a vegetable peeler, shave zucchini into ribbons, running blade down the length. Stop shaving once you get to the seedy core. Finely chop core.

Melt 1 TBSP butter in a large, tall-sided pan or medium pot over medium heat. Add garlic and zucchini core. Cook, tossing, until softened, about 3 minutes. Add rice and cook, stirring, until grains are translucent, 1-2 minutes.

Add stock ½ cup at a time to pan with rice, stirring after each addition. Allow rice to absorb most of stock before adding more. Continue until grains are al dente and creamy, 25-30 minutes. Season with salt and pepper.

While risotto cooks, heat a drizzle of olive oil in another large pan over medium heat. Add zucchini ribbons. Season with salt and pepper. Cook, tossing, until tender and softened, about 5 minutes. Add a squeeze of lemon juice and toss.

Stir shallots and Parmesan into risotto. Season with salt and pepper. Divide risotto between plates and top with zucchini ribbons.