In a prep bowl grate the garlic and ginger. Mash into a paste (easier with mortar and pestle if you have it).
Turn Instant Pot (or other pressure cooker) to saute mode and add the butter. When the butter melts add the onions. Cook until onions begin to brown, 6 - 7 minutes, stirring occasionally.
Add the garlic ginger paste and serrano pepper. Cook for another 1 - 2 minutes, stirring, until fragrant. Stir in the partially drained diced tomatoes. Use the liquid to deglaze the pan, scraping bits from the bottom. Cook for another 1 - 2 minutes.
Add the spices and mix ingredients well, another 1 - 2 minutes, until fragrant. Add the ground lamb and cook until browned, 3 - 4 minutes.
Add the beef broth and fully de-glaze the pan (this will help avoid the dreaded burn notice when the pot comes up to pressure). Once the pan is deglazed, add in the carrots, peas, turnips, and tomato sauce and mix well.
Secure the lid and set the pot to 10 minutes on high pressure. While the pressure cooker is coming to pressure start the rice according to the package instructions.
Natural release the pressure. If still under pressure after 20 minutes or so, quick release.
Serve in bowls over jasmine rice, top with cilantro and fresh diced tomato (optional).