How can I roast a 90 pound pumpkin without an oven?

My boyfriend got me a 90 lb pumpkin, and my plan is to roast it to make puree for cooking and baking. I wish I could include pictures because this thing is huge! We’ve already scooped out the insides, peeled the rind, and chopped the flesh into pieces for roasting. The pumpkin itself is pretty bland, so I want to roast it to bring out some flavor before turning it into puree. The only issue, I don’t currently have a working oven but I do have a grill and stove top. Does anyone have advice on how to roast or cook the pumpkin on a grill (or any other method without an oven) to get a similar caramelized flavor? Any tips on managing moisture, temperature, or batch size would be super helpful! submitted by /u/nika824