Measure the Sesame Ginger Marinade ingredients - except salt and pepper - into a small bowl, whisk to combine.

Season with salt and pepper to taste, set aside.

Thaw your tuna safely - either in cold water for 30 minutes, or in the fridge overnight.

Blot the tuna steaks dry, cut into 1" cubes, and gently place in a large freezer baggie. Pour the prepared marinade into the baggie, gently mix to coat the tuna, set aside.

Wash your vegetables.

Slice the zucchinis into ¾" rounds, place in a the baggie. Seed the bell peppers, chop peppers and onion into 1" cubes, add to the baggie.

Gently stir the ingredients to coat the vegetables with excess marinade.

Seal the baggie - gently pressing out most of the excess air, chill for at 30 minutes.

Get a good fire going, aiming for a high heat. You can cook your tuna kebabs on a camp stove, over hot coals, or even over the open flame of a fire pit.

Use a slotted spoon to remove tuna and veggies from the marinade.

Thread the prepared ingredients onto your skewers, alternating a piece of tuna, with a pieces of peppers, zucchini, and onions

Spray the grill grate with grill spray, then arrange the skewers in a single layer, leaving some room between each skewer. Depending on the size of your grill, you may need to work in batches.

Cook for about 2-3 minutes, until tuna sears on one side.

Spray the tops of the skewers with nonstick cooking spray, and flip the skewers. Continue grilling another 2-3 until tuna is seared on the second side, and tuna is as cooked as you like it.

Remove tuna skewers from heat and sprinkle with sesame seeds. Serve hot, with a side salad or rice, if desired.