Cajun-Style Shrimp and Grits

INGREDIENTS

• 1 tablespoon olive oil
• 2 ounces tasso ham, minced (1/2 cup)
• 1 cup chopped onion
• 1 garlic clove, minced
• 36 medium shrimp, peeled (about 1 1/4 pounds)
• 1 teaspoon Cajun seasoning
• 2 1/4 cups water, divided
• 1 tablespoon unsalted butter
• 1 cup fat-free milk
• 1/4 teaspoon salt
• 1 cup uncooked quick-cooking grits
• 4 ounces sharp cheddar cheese, shredded (about 1 cup)
• 1/2 cup sliced green onions