Grilled Turkey & Mushroom Pesto Burgers

Recipe courtesy of Renee from Sugarbean.
Ingredients
1 tbsp olive oil
1 cup cremini mushrooms, diced small
1 medium onion, diced small
1 pound (454 grams) lean ground turkey
1 egg, beaten
1 tbsp pesto
1/2 tsp salt
fresh pepper
4 fresh Kaiser buns
sliced tomatoes
lettuce
cheddar slices
cooked bacon
pesto mayo (mix equal amounts of pesto and mayo together)
Method
1. To make onion jam, heat olive oil over medium/high heat in medium size sauce pan. Add onions, stirring well, reduce heat to medium/low and stir in salt. Cook until translucent, stirring often.
2. Reduce heat to low and cook for 20 minutes, scraping up brown bits every so often. You may need to add a bit more olive oil if it seems too dry. Add the balsamic vinegar and brown sugar and cook about 20 minutes longer, over low heat, stirring often. Once soft and jammy, let cool and set aside.