Place butter, garlic and shallots into the cooking pot. Keep the lid open and select SAUTE program. Cook and stir 4 minutes or until softened. Add the white wine and tomatoe; stir well.
Add mussels, 4 lemon quarters, parsley, thyme, and bay leaf; stir to combine. Close and lock the lid. Select PRESSURE COOK program Level 7 and Time 4 minutes.
Once the timer beeps 3 times to indicate the end of cooking, manually release pressure by pressing on the steam release button for about 5 seconds . The steam release process will take about 4 to 5 minutes.
Slowly open the lid and carefully remove mussels. Place on a large platter and squeeze the juice from the remaining lemon quarters over the mussels. Sprinkle with additional parsley and serve with French bread.