Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.

Thinly slice chives. Halve, peel, and dice onion. Trim, peel, and dice carrot. Zest half the orange (you’ll need about ¼ tsp zest; ½ tsp for 4 servings; use remaining orange however you like).

In a small bowl, combine mayonnaise, crème fraîche, half the chives, and half the romesco (all for 4). Set aside.

Slice baguette crosswise on a diagonal into 8 slices (16 slices for 4 servings). Spread out on a baking sheet and drizzle with oil. Toast on top rack until golden brown, 5-10 minutes.

Transfer crostini to a plate. (Reserve baking sheet.)

While baguette toasts, heat a large drizzle of oil in a medium pot over medium-high heat. Add onion, carrot, garlic powder, 1 tsp herbes de Provence (2 tsp for 4 servings), salt, and pepper. (Be sure to measure the herbes de Provence—we sent more!) Cook, stirring occasionally, until softened, 3-5 minutes.

Add tomato paste. Cook, stirring occasionally, until fragrant, 30-60 seconds.

Stir in potatoes, stock concentrates, orange zest, half the basil paste, and 1¾ cups water (all the basil paste and 3½ cups water for 4). Bring to a boil, then reduce heat to medium; simmer until slightly thickened, 6-8 minutes.

Reduce heat to low; taste and season with salt and pepper. Keep on low heat until ready to serve.

Meanwhile, pat cod* dry with paper towels; season with salt and pepper.

Lightly oil baking sheet used for crostini. Add cod to sheet; bake on top rack until fish is cooked through and flakes easily with a fork, 10-12 minutes.

While cod cooks, pat scallops* dry with paper towels. Remove side muscle and season all over with salt and pepper.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add scallops and cook until opaque and cooked through, 2-3 minutes per side.

Turn off heat; transfer to a plate. Tent with foil to keep warm.

While cod roasts, pat scallops* dry with paper towels. Remove side muscle from scallops and season all over with salt and pepper.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add scallops and cook until opaque and cooked through, 2-3 minutes per side.

Turn off heat; transfer to a plate. Tent with foil to keep warm.

Spread romesco aïoli over crostini (if desired, drizzle any remaining aioli over the fish while plating).

Divide veggies and broth between bowls. Top with cod; place scallops around cod. Garnish with remaining chives and serve with romesco crostini.