Wash and dry all produce. Pick basil leaves from stems; set leaves aside. Combine 4 cups water (7 cups for 4 servings), stock concentrates, and basil stems in a medium pot. Bring to a boil, then turn off heat. Slice corn kernels off cob. (TIP: Do so over a bowl for less mess.) Halve zucchini lengthwise; scoop out and discard seeds with a spoon, then dice zucchini into 1/4-inch pieces. Halve, peel, and finely dice onion.

Melt 1 TBSP butter (2 TBSP for 4 servings) in a large pan over mediumhigh heat. Add corn and zucchini and cook, stirring occasionally, until veggies are softened and lightly browned, 5-7 minutes. Season with salt and pepper. Turn off heat; transfer to a large bowl. Wash out pan.

Heat half the garlic oil in same pan over medium-high heat. Add onion, rice, and Italian Seasoning. Season generously with salt and pepper. Cook, stirring, until onion is softened and rice is translucent, 2-3 minutes. Leaving basil stems in pot, add 1/2 cup stock to rice mixture; stir to combine. Reduce heat to medium.

Continue adding stock (leaving stems in pot) 1/2 cup at a time to pan with rice, stirring after each addition. Allow rice to absorb most of the liquid before adding more. Repeat process until rice is al dente and mixture is creamy, 25-30 minutes. Meanwhile, zest and quarter lemon. Stack basil leaves, then roll up lengthwise and slice crosswise into thin ribbons.

Stir veggies and half the basil leaves into risotto. Cook, stirring, until warmed through, 1-2 minutes. Turn off heat and stir in half the Parmesan and 1 TBSP butter (2 TBSP for 4 servings) until melted. Squeeze in lemon juice to taste and season with salt and pepper.

Divide risotto between bowls. Garnish with remaining Parmesan, basil leaves, and garlic oil. Top with a pinch of chili flakes and as much lemon zest as you like. Serve with remaining lemon wedges on the side.