Prepare stock: Warm the chicken or vegetable stock in a saucepan over low heat.
Cook aromatics: In a large skillet or saucepan, heat butter and olive oil. Add onion/shallots and cook until softened, about 3–4 minutes. Stir in garlic and cook 30 seconds.
Toast rice: Add Arborio rice and cook, stirring, until edges are translucent, about 2 minutes.
Deglaze with wine: Pour in white wine and stir until fully absorbed.
Cook risotto: Add warm stock ½ cup at a time, stirring frequently, and allowing each addition to absorb before adding more. Continue until rice is creamy and tender, about 18–20 minutes.
Finish risotto: Stir in Parmesan, lemon zest, lemon juice, salt, and pepper. Keep warm.
Prepare scallops: Pat scallops dry with paper towels (very important for searing). Season with salt and pepper.
Sear scallops: Heat olive oil in a skillet over medium-high heat. Add scallops and sear 2–3 minutes per side until golden brown and just cooked through. During the last minute, add butter to the pan and spoon over scallops.
Serve: Spoon risotto onto plates, top with scallops, garnish with parsley, and serve with lemon wedges.