Grilled vegetables are often an afterthought, but they should not be. The grill does something to vegetables that roasting in an oven simply cannot replicate: it adds direct char, smoke, and caramelisation all at once. These are some of the vegetables that respond best to the grill and how to handle each one.
Peppers
Bell peppers and chilli peppers both grill exceptionally well. For bell peppers, slice them into thirds or halves and remove the seeds and white pith. Brush with oil and grill over medium-high direct heat for 8 to 10 minutes, turning once or twice. You want char on the outside and soft, sweet flesh underneath. For a deeper smoky flavour, grill whole peppers until the skin blisters all over, then put them in a covered bowl for 10 minutes. The steam loosens the skin and you can peel it off easily.
Courgettes (Zucchini)
Cut courgettes lengthways into planks about half a centimetre thick, or into rounds for a more hands-off approach. Brush with olive oil, season generously with salt and pepper, and grill over medium-high direct heat for 3 to 4 minutes per side. Courgettes release a lot of moisture, so do not crowd them. They should have clear grill marks and be tender but not mushy. Thin slices cook fast and are easy to overcook, so watch them.
Corn on the Cob
Corn is one of the most forgiving vegetables on a grill. You have two options. Grill it in the husk: soak the whole ears in water for 20 minutes, shake off the excess, and grill over medium heat for 15 to 20 minutes, turning every few minutes. The husk steams the corn inside and protects it from burning. Pull back the husk for the last few minutes to get some colour on the kernels.
Alternatively, shuck the corn and grill it directly over medium heat for about 10 minutes, turning regularly. You get more char this way, which many people prefer.
Asparagus
Asparagus needs minimal prep. Snap off the woody ends, toss the spears in oil, season with salt, and they are ready to grill. Because they are thin, they can fall through the grates. Group them together or use a grilling basket. Grill over medium-high direct heat for 3 to 5 minutes, turning once. They should have some char but still have a little bite. Thicker spears take longer than thin ones.
Asparagus benefits from a squeeze of lemon and some coarsely grated parmesan after coming off the grill. The heat just off the grill is enough to slightly melt the cheese.
Mushrooms
Large portobello mushrooms are outstanding on the grill. Wipe them clean with a damp cloth, brush with oil on both sides, and season well. Grill gill-side up first over medium-high direct heat for about 5 minutes, then flip and cook for another 3 to 4 minutes. They have enough structure to grill flat without falling apart. Smaller mushrooms are better in a grill basket with some oil and seasoning, tossed over medium heat for 8 to 10 minutes.
General Prep Principles
Whatever the vegetable, a few rules apply consistently. Do not skip the oil. Vegetables without a fat coating stick to the grates and dry out. Use enough oil to coat lightly but not drench.
Season before grilling, not just after. Salt draws out moisture from the surface, which helps with browning and caramelisation.
Cut consistently. Uneven pieces cook unevenly. Aim for similar thickness across any batch.
Medium to medium-high heat works best for most vegetables. Screaming hot direct heat chars them before they soften inside. If the vegetables are burning on the outside but still raw in the middle, move them to a cooler zone or reduce the heat.
Grilled vegetables are often best served simply: a drizzle of good olive oil, some flaky salt, maybe a squeeze of acid. The grill has already done most of the flavour work.