Thaw and cut bison sirloin steaks into 1-inch pieces, place in bowl, and set aside.
In a large bowl, combine olive oil, vinegar, garlic, black pepper, oregano, basil, thyme, and sea salt to make marinade. Add vegetables to marinade, and toss to coat. Assemble vegetable skewers, alternating vegetables. Continue until all vegetables are gone.
Add bison sirloin to remaining marinade left over in the mixing bowl, and toss to coat. Assemble bison skewers with remaining skewers.
Place vegetable skewers on the well-heated grill 2-3 minutes before adding the bison skewers. They will take longer to cook.
Turn vegetable skewers over once, and then add bison skewers to the grill. Cook for about 3-4 minutes, turn bison skewers, and cook and additional 3-4 minutes, or until done (8-11 minutes total cooking time).