Bring first 3 ingredients to a boil in a saucepan over medium-high heat. Gradually whisk in cornmeal and flour; cook mixture, whisking constantly, 10 to 12 minutes.
Remove from heat, and stir in crabmeat and Asiago cheese. Pour mixture into a greased 9-inch loafpan, and chill 8 hours.
Unmold and cut polenta into 1/2-inch slices. Cut each slice into 2 triangles.
Melt 2 tablespoons butter in a large skillet over medium-high heat; cook half of polenta triangles in melted butter until lightly browned, turning triangles once. Repeat procedure with remaining 2 tablespoons butter and polenta triangles. Serve polenta with Horseradish Cream.
*Note: Mild Cheddar or Edam cheese may be substituted.