In Step 2, it says to cook the onions until they're beginning to brown, about 25 minutes. Do you mean 2-5 minutes?

Yes, slow is right. If the heat is too high, they will burn. I normally take about 40 minutes. Stir often. You can cheat a bit and add a sprinkle of sugar if the onions are not sweet enough. Walla walla, videlia, bermudas and other sweet onions are best. Do not cover or they will steam instead of saute. Make more than you think as they reduce dramatically. Save the amount you do not need for another day. Nice on toast points with some brie.

No. Caramelizing onions takes a long time. 25 minutes is accurate.