Step 1

Lightly grease a 3-quart baking dish. Preheat oven to 350°F.

Step 2

Melt butter in a Dutch oven over medium; stir in onion and garlic, and cook, stirring constantly, 2 minutes. Stir in water and salt, increase heat to medium-high, and bring to a boil. Whisk in grits, and stir in ham; return to a boil. Reduce heat to medium-low, and simmer, whisking occasionally, until thickened and grits are almost tender, 15 to 20 minutes.

Step 3

Remove from heat; add both cheeses, stirring until completely melted. Stir in milk, corn, thyme, pepper, and eggs. Spoon mixture into prepared baking dish.

Step 4

Bake in preheated oven until golden and cooked through, 50 minutes to 1 hour. Let stand 15 minutes before serving.