Adjust racks to top and middle positions and preheat oven to 375 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges.

Pick and roughly chop fronds from dill.

Toss potatoes on a baking sheet with a drizzle of olive oil, half the dill, salt, and pepper.

Roast on top rack until potatoes are lightly browned and tender, 30-35 minutes. Transfer to a plate; cover with foil to keep warm.

While potatoes roast, zest lemon and halve lengthwise; thinly slice half the lemon into half-moons. Cut remaining lemon into wedges.

Halve, peel, and thinly slice shallot. Peel and thinly slice garlic. Halve tomato lengthwise, then thinly slice into half-moons. Trim and slice zucchini crosswise into ½-inch-thick rounds.

Pat cobia* dry with paper towels and place in a large bowl.

Season cobia with a drizzle of olive oil, lemon zest, remaining dill, salt, and pepper. Rub to evenly coat fish.

Cut two 10-inch-long pieces of parchment paper or foil (four pieces of parchment or foil for 4 servings); arrange pieces on a work surface with a long side facing you.

Dividing evenly, arrange shallot lengthwise in the center of parchment or foil pieces. Top with garlic and tomato. Season with salt and pepper.

Lay seasoned cobia on top of tomato. Shingle as many lemon half-moons as you like on top of fish, then top each with 1 TBSP butter.

For each cobia oven packet, bring the two long sides of parchment or foil toward the center and fold down several times until there is about 1 inch of space between parchment or foil and fish and the seal is secure. 

Roll the shorter ends of parchment or foil tightly to seal packets. (TIP: Tightly sealing the packets will ensure that the fish steams properly.) Set aside.

Place zucchini in a second large bowl. Toss with a large drizzle of oil, Fry Seasoning, salt, and pepper.

Arrange zucchini on one side of a second baking sheet in a single overlapping layer. TIP: Be sure to shingle the zucchini in a single layer so they cook evenly.

Place cobia oven packets on empty side of baking sheet.

Roast on middle rack until zucchini is tender and cobia is fully cooked, 18-20 minutes.

Meanwhile, in a small bowl, whisk together mayonnaise and Dijon.

Divide cobia oven packets, potatoes, and zucchini between plates. Carefully cut a 3-inch slit in top of packets alongside the fold. TIP: If cobia isn’t fully cooked yet, carefully return opened packets to baking sheet and roast for a few more minutes.

Serve with Dijonnaise for dipping and remaining lemon wedges on the side. TIP: When you’re ready to eat, gently pull the oven packets apart at slit to open (careful—steam will be released) and push aside the lemon slices!