Place all the vegetables in a large bowl drizzle with oil and season with salt and pepper.
Preheat barbeque to medium high heat 375°F (190°C).
Place well oiled sweet and Poblano peppers on the grill and cook for approximately 3-5 minutes per side, until skin is nicely charred and peppers are soft. Remove from the grill and place them in a paper bag or under plastic wrap to steam making the skin loose and easy to remove.
Place the remaining vegetables on the grill.
Cook asparagus and onions for 2-4 minutes until charred, but not soggy. Cook corn on the cob for 5 minutes or until yellow colour of the corn brightens. Cook potatoes for 5 minutes.
Remove vegetables from the grill.
Peel skin from the peppers, remove seeds and chop.
Chop remaining vegetables into bite sized pieces.
Strip the corn from the cob.
In a medium bowl mix together eggs, cream, crumbled cheese and season with salt and pepper.
Prepare barbeque for direct and indirect cooking. Leave 2 burners turned on and one burner turned off. Preheat to 400°F.
Preheat a cast iron pan on the grill at temperature of 400°F keep the lid closed on the barbeque for about 10 minutes.
Add oil and butter (for flavour) to the pan.
Add all the chopped vegetables to the pan and cook until vegetables begin to sizzle.
Pour the egg mixture over the vegetables and stir like an omelette until egg starts to set slightly.
Slide the skillet over to the indirect heat side of the barbeque. Close barbeque lid and cook for approximately 10 –12 minutes.
Cook until eggs are set.
Cut the frittata into wedges and serve it immediately, or cool and serve it at room temperature.