Yellow mustard, barbecue sauce, or ketchup for serving
Slice the sausage links lengthwise about 1/2 way through, like you’re butterflying them.
If using a lean sausage (less than 10 g fat per link) add a teaspoon of oil to a large skillet. Heat the skillet over medium-low heat and brown the sausages on all sides slowly. If your sausage is real fatty, you can just brown them without additional oil.
Once browned, add the onions and pepper and increase the heat to brown the onions a little bit. th
Add the beer and cook, uncovered, over medium-high heat until evaporated. The onions should be cooked by now.
Open the sausages and cook them cut sides down in the skillet for a few minutes to brown.
Heat tortillas and place a sausage and some onions and peppers in each one. Top with condiments of choice, roll up and eat!