"Stout" Sausages

A quick one, improvised by some leftover stout and the acquisition of a hefty farmer's market onion (I wanted to play with its taste rather than lose it in a larger meal):

1 lb. Italian Sausage
2 peppers [sliced] (either green, red, or yellow--I like at least one green to balance the meal's color)
1 onion [sliced]
6 garlic cloves [roughly chopped]
3/4 c. stout (or experiment with another beer--Yuengling has worked well in other manifestations)
3 dashes of red pepper flakes

1. Heat oven to 400º.
1. In cast-iron heat sausages on medium-high heat, 10 mins. Remove.
2. Add garlic. When flavor released, add peppers & onion, sprinkle with salt to taste and red pep. flakes, 8 mins.
3. Add sausages & beer. When boils, put in oven, 25 mins.
4. Serve on rolls, plain or with Dijon mustard.