1 , stemmed, seeded, and finely chopped (Such As Jalapeno)
1⁄4 Cup (4 tbs)
Toast mustard seeds in a 6- to 8-inch frying pan over medium heat just until seeds begin to pop, 2 to 5 minutes, shaking pan frequently.
Trim ends off lemons.
Cut lemons in half crosswise, then cut each half into about 1-inch wedges; pluck out obvious seeds.
Place lemons in a nonmetallic 2 1/2- to 3-quart bowl; stir in chile (if used), salt, cayenne, oil, and mustard seeds.
Cover bowl with plastic wrap.
Microwave on HIGH (100%) until mixture is slightly thickened and lemons are easy to pierce, 16 to 20 minutes, stirring every 4 minutes.