Peel the sweet potatoes and cut into 3cm chunks. Crush or finely chop the garlic. Halve the carrot lengthwise and cut into 2cm chunks. Coarsely chop the broccoli stem, then cut the head into small florets. Cut the lemon into wedges. Cut the fish into 3cm chunks.
Step 2 — Cook sweet potato
Put the sweet potato in a medium saucepan, cover with cold salted water and bring to the boil. Reduce the heat to medium and cook for 12-14 mins until tender. Drain well, return to the pan and cover to keep warm. (The secret to fluffier mash is well drained sweet potato.)
Step 3 — Crumb fish
Meanwhile, bring a separate medium saucepan of water to the boil for the vegetables. Put 1 tbs flour in a shallow dish. Whisk 1 egg in a bowl. Combine the garlic, breadcrumbs and country seasoning in a separate shallow dish. Dust the fish with the flour, shake off the excess, then dip in the egg and coat in the breadcrumb mixture.
Step 4 — Cook vegetables
Cook the carrot in the pan of boiling water for 3 mins. Add the broccoli and cook for a further 3 mins or until tender. Drain, then return the vegetables to the pan. Add 2 tsp extra virgin olive oil, squeeze over the juice of 1 lemon wedge, season with salt and pepper and gently toss to coat the vegetables.
Step 5 — Cook fish
While the vegetables are cooking, heat 1cm oil in a medium frypan over medium heat until hot. Cook the fish for 4 mins each side until golden and cooked through. Remove from the pan and drain on paper towel.
Step 6 — Mash sweet potato
Mash the sweet potato until smooth. Add 20g butter and 2 tsp dijon mustard and stir until creamy. Taste, then season with salt and pepper. Divide the mash, vegetables and fish among plates. Serve with the aioli and remaining lemon wedges.