What is the fastest way to cook a Meat Salad?
Since I cannot speak to the benefits of the convection or grill modes of your microwave, I would use the main setting.

In the context of a salad setting, although you want moist meat, sausage would produce a bit much grease. If the grill setting can actually cauterize the meat without creating too much grease, or if you can capture the runoff (i.e. with a bacon microwaving plate), it would be more beneficial. In many cases, though, the microwave will soften the sausage, then cause it to dry out (again, you will want to capture the grease for the sake of the salad). Nonetheless, it seems like the microwave is a poor alternative, and (if it is smoked/pre-cooked sausage) you might better to just eat it cold.

That said, if the problem is that you are just looking for an alternative to steaming and then frying, have you consider braising, searing, grilling (if possible)? You could also do a marinade to moisten the meat and then do a quick, very high-temp fry (in a skillet) to just crust the marinade and heat the meat. These all seem faster or simpler than steaming and frying.