Spring onions are perfect for grilling Tiny spring onions just need their tops and roots trimmed, and a layer of skin removed. They can then be grilled whole, after brushing with olive oil and seasoned with salt and pepper.
If the onions are larger than your thumb, peel and trim and then blanch in salted water until just tender. Remove and season with olive oil, salt and pepper for grilling.
Grill the onions side by side over a moderately hot fire. Turn every few minutes so that they brown evenly. Small spring onions grilled raw will take 12 to 15 minutes. Parboiled larger ones will take only 5 or 6 minutes.
When the onions are done, arrange on a warm platter and drizzle on a little more olive oil. Sprinkle with lemon juice or some good balsamic vinegar.
Thick slices of larger onions can also be grilled. Keep the slices intact and grill as above for 10 to 12 minutes, turning once with a spatula, until well-browned and tender.