Prep the ingredients: Preheat the oven to 350 degrees. In a small pot, bring 1 cup water with a large pinch of salt to a boil. Zest and halve the lime. Cut one half into wedges. Halve, peel, and finely chop the shallot. Halve the tomatoes. Trim the ends of the green beans.
Cook the quinoa: Add the quinoa to the boiling water, cover, and reduce to a low simmer for 15-20 minutes, until tender. Season with salt and pepper.
Make the wasabi aioli: In a small bowl, combine the mayonnaise, lime zest, a squeeze of lime (to taste) and the wasabi (to taste). Season with salt and pepper.
Make the panko crust: In a medium pan, melt 1 Tablespoon butter. Toss the panko into the melted butter and season with salt and pepper. Transfer the panko to a plate and wipe out the pan.
Cook the mahi mahi: Season the mahi mahi on all sides with salt and pepper. Spread the top of each fillet with 1 teaspoon of wasabi aioli. Press the panko onto the top of each fillet and place onto a lightly oiled baking sheet. Bake in the oven for about 10 minutes, until flaky and opaque.
Sauté the green beans and tomatoes: Meanwhile, heat 1 Tablespoon butter in the same pan over medium heat. Add the shallot and green beans and cook, tossing, for 4-5 minutes, until the shallots are softened. Add a splash of water to the pan and let the green beans steam until tender. Add the tomatoes and cook, tossing, for another 1-2 minutes, until heated through. Season with salt and pepper.
Plate: Serve the panko-crusted mahi mahi on a bed of veggies and quinoa. Serve with the remaining wasabi aioli and a wedge of lime.