Step 1

Combine all ingredients in a heavy sauce pan. Whisk over medium heat until butter melts and sauce is well blended.

Step 2

Season to taste with salt and pepper. (Can be made 3 hours ahead. Cool. Whisk over low heat to rewarm before using.)

Step 3

Cut zucchini, carrots and onions about 1/4" thick.

Step 4

Slice bell peppers into quarters

Step 5

Skewer the mushrooms if using small mushrooms or remove tough center stem if grilling portobello mushrooms.

Step 6

Brush both sides of veggies with marinade. They can be wrapped and refrigerated if making them ahead. Remove from fridge about 30 minutes before grilling.

Step 7

Over a medium heat, begin grilling vegetables starting with thickest vegetables first (carrots) and end with the most delicate last. (Asparagus needs just a few minutes)

Step 8

If there's extra sauce, reheat it and serve it on the side or drizzle over warm vegetables.