Step #1 Melt the butter in a medium saute pan over med-heat/flame; add onion & cook, stirring every once in awhile, until translucent, about 5 mins.
Step #2 Add the wine & water; increase the heat to high & bring to a boil; slowly add the cornmeal, whisking constantly to prevent lumps.
Step #3 Reduce the heat to low & cook,until the mixture is a smooth creamy paste, continuing to stir contstantly, about 10 mins.
Step #4 Stir in the Parmesan cheese,and pepper; evenly spread the mixture in a lightly oiled 9-inch pie plate; Refrigerate until firm,(when polenta is cool, salt, at least 2 hrs, cover with plastic wrap.
Step #5 ).
Step #6 When ready to serve, lightly brush the surface of the polenta with olive oil, halve the polenta & cut each halve into 3 triangles.
Step #7 Heat a large nonstick skillet over mediun-high heat; arrange the triangles in a single layer; lightly brush tops with olive oil, cook this until lightly browned, about 2 mins per side.
Step #8 Note: If you prefer, the triangles can be cooked on a stove-top grill pan over med-heat/flame or can be broiled on a baking sheet under the oven broiler; the time remains about 2 mins per side.